Observation of the Spin-Glass Behavior in Co-Based Antiperovskite

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Observation of the Spin-Glass Behavior in Co-Based Antiperovskite Nitride GeNCo3 Lin Zu,†,‡ Shuai Lin,*,† Jianchao Lin,† Bin Yuan,† Xucai Kan,†,‡ Peng Tong,† Wenhai Song,† and Yuping Sun*,§,†,∥ †

Key Laboratory of Materials Physics, Institute of Solid State Physics, and §High Magnetic Field Laboratory, Chinese Academy of Sciences (CAS), Hefei 230031, People’s Republic of China ‡ University of Science and Technology of China, Hefei 230026, People’s Republic of China ∥ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People’s Republic of China S Supporting Information *

ABSTRACT: Single-phase antiperovskite nitride GeNCo3 with space group Pm3m ̅ is successfully synthesized by a solid−gas reaction. The crystal structure, magnetism, specific heat at low temperatures, Hall effect, and electrical and thermal transport properties are widely investigated. Exhilaratingly, a canonical spin-glass (SG) behavior is observed in GeNCo3 with a freezing temperature T0 = 79.43 K, dynamical exponent zν = 6.156, and flipping time τ0 = 5.0 × 10−12 s. The origin of the SG state in GeNCo3 is likely due to the atomic disorder introduced by the Ge vacancies. This is further proven by the measurements of Ge0.9NCo3 with more Ge deficiencies.

conductivity,28 SG behavior,9 and ZFC exchange bias.9 Here, based on the 3d electron state of Co (∼3d74s2), Co-based antiperovskite nitrides ANCo3 can be considered as electrondoped ANCr3/Mn3/Fe3 (Cr ∼3d54s1, Mn ∼3d54s2, Fe and ∼3d64s2) or hole-doped ANNi3 (∼3d84s2). Therefore, it is very possible that similar physical properties observed in ANCr3/ Mn3/Fe3/Ni3 or some novel physical properties are existed in Co-based antiperovskite nitrides ANCo3. However, the experimental and theoretical researches on Co-based antiperovskite nitrides are rare and mainly focused on In/Cd/ CuNCo3.29−31 Thus, it will be necessary and important to investigate other Co-based antiperovskite nitrides. As a typical Co-based antiperovskite nitride, GeNCo3 is little reported experimentally because of the difficulty for the preparation of a single-phase sample, and its physical properties are mysterious. In this work, single-phase polycrystalline GeNCo3 was successfully synthesized, and investigations of the structure, electrical transport, magnetism, and thermal transport were performed. Interestingly, typical SG behavior was observed in GeNCo3. To further investigate the SG state, we measured the field and frequency dependence of the

1. INTRODUCTION Recently, the antiperovskite structural compounds AXM3 (A = Ga, In, Sn, Al, Zn, Ge, Cu, etc.; X = C or N; M = Ni, Co, Fe, Mn, etc.) have attracted considerable attention because of their quite simple structure (cubic structure) and abundant physical properties such as magnetocaloric effect,1 superconductivity,2 giant magnetoresistance effect,3,4 spin-glass (SG) behavior,5−9 giant barocaloric effect,10 negative thermal expansion,11 and magnetstriction and nearly zero temperature resistivity cofficient.12,13 As we all know, the antiperovskite nitride ANM3 is a very important branch of antiperovskite compounds. Also, a lot of interesting physical properties and potential functionalities mentioned above are observed in ANM3. According to the previous theoretical investigations, the physical properties of antiperovskite nitrides ANM3 are mainly determined by M-3d electrons in ANM3.14,15 Experimentally, plenty of interesting properties are indeed observed in ANM3 (M = Ni, Fe, Mn, and Cr), and they are always somewhat at variance with different M elements: Ni-based nitride ANNi3 (A = Cu and Zn) show remarkable superconductivity,16,17 Febased nitrides ANFe3 (A = Au, Pd, Mn, Fe, Ag, Pt, and Ni) show Invar-like behavior,18−26 manganese nitrides ANMn3 (A = Zn, Ge, Ga, and Cu) display large NTE,11,27 and Cr-based nitrides ANCr3 (A = Ga, Pd, Rh, and Pt) exhibit super© XXXX American Chemical Society

Received: June 23, 2016

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DOI: 10.1021/acs.inorgchem.6b01462 Inorg. Chem. XXXX, XXX, XXX−XXX

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Figure 1. (a) Rietveld-refined powder XRD patterns at room temperature for GeNCo3. The vertical marks (blue line) stand for the positions of the Bragg peaks, and the solid line (green line) at the bottom corresponds to the difference between the experimental and calculated intensities. (b) Temperature-dependent magnetization M(T) curves for GeNCo3 at an applied field of 100 Oe under ZFC and FC processes between 5 and 300 K. Inset: Isothermal M(H) curves at 5 and 300 K for GeNCo3. (c) Temperature-dependent resistivity ρ(T) (2−350 K) for GeNCo3. Inset: lower-T ρ(T) data plotted as ρ(T) versus T2. The solid line represents the linear fitting results according to eq 1. (d) Temperature-dependent heat capacity CP(T) between 5 and 50 K for GeNCo3. Inset: Plot of CP(T)/T versus T2 below 20 K. The solid line represents the linear fitting results according to eq 2. (e) Temperature-dependent total thermal conductivity κtotal, electronic thermal conductivity κe, and lattice thermal conductivity κL for GeNCo3. (f) Temperature-dependent Seebeck coefficient α(T) in a temperature range of 5−330 K for GeNCo3. Inset: ρxy(H) curve at 300 K for GeNCo3.

2. EXPERIMENTAL DETAILS

performed on a Quantum Design superconducting quantum interference device (SQUID-5T) magnetometer. The electrical transport, low-temperature specific heat, Hall coefficient, thermal conductivity, and Seebeck coefficient were carried out on a Quantum Design Physical Property Measurement System (PPMS-9T). Thermogravimetric analysis (TGA) was performed on a Pyris 1 thermogravimetric analyzer.

Single-phase polycrystalline GeNCo3 was synthesized by using a solid−gas reaction, which has been confirmed to be an effective way to prepare 3d transition-metal nitrides.32−34 As starting materials, GeO2 (4N) and Co (3N) powders were mixed in the desired proportion, thoroughly ground, and then placed in a quartz tube. The quartz tube along with the mixtures was put into a tube furnace and heated at about 923 K for 10 h under a flowing NH3 atmosphere (∼600 mL/ min). After that, the tube furnace natural cooled to room temperature. In order to carry out magnetic and electrical transport measurements, the intermediate samples were thoroughly ground again, pressed into thin pellets (at a pressure of 25 MPa), and heated for another 5 h under the same conditions as before. X-ray diffraction (XRD; Philips, Cu Kα, λ = 0.15406 nm) was carried out around room temperature. The Rietveld refinement of the XRD pattern was performed using Rietica software. Our samples’ chemical compositions were measured by energy-dispersive X-ray spectroscopy (EDS). Characterization of the magnetic properties was

3. RESULTS AND DISCUSSION 3.1. Characterizations of the Physical Properties. The XRD pattern of GeNCo3 at room temperature is displayed in Figure 1a. The intense peaks can be indexed based on the cubic antiperovskite structure (space group Pm3̅m). The antiperovskite structure was used as an initial model, unit-cell refinement was performed, and the refined structural parameter values (such as χ2, Rp, and Rwp) are very small, as listed in Table 1, indicating that the sample of GeNCo3 is quite good in quality. The lattice parameter determined by Rietveld refinement is 3.6297(5) Å, which is larger than the value of GeN1−xCo3 previously reported (∼3.61 Å).35 Figure 1b shows the temperature dependence of magnetization M(T) curves for GeNCo3 with a magnetic field of 100

alternating-current (ac) susceptibility, the temperature dependence of direct-current (dc) magnetization at different magnetic fields, and the magnetic relaxation. Furthermore, the origin of this SG state in GeNCo3 was discussed.

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DOI: 10.1021/acs.inorgchem.6b01462 Inorg. Chem. XXXX, XXX, XXX−XXX

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obtained. The calculated Debye temperature ΘD is 318 K using the formula36

Table 1. Fitting Parameters of the Crystal Structure, Electrical Transport, and Low-Temperature Specific Heat for GeNCo3 compound cryst syst space group lattice constant (Å) cell volume (Å3) α/β/γ (deg) Rp (%) Rwp (%) χ2 ρ0 (μΩ cm) A (μΩ·cm/K2) γ (mJ/mol·K2) β (10−2 mJ/mol·K4) δ (10−5 mJ/mol·K6) ΘD (K)

⎛ n × 1.94 × 106 ⎞1/3 ΘD = ⎜ ⎟ β ⎝ ⎠

GeNCo3 cubic Pm3̅m 3.6297(5) 47.82 90/90/90 2.40 2.90 1.007 351.49 0.0067 48.42 30.16 −46.67 318.0

where n stands for the number of atoms per formula unit, and here n is 5 for GeNCo3.The γ, ΘD, β, and δ values of GeNCo3 are summarized in Table 1. In general, the Kadowaki−Woods ratio (RKW) is defined as RKW = A/γ2, where γ represents the Sommerfeld constant and A stands for the T2-term coefficient of the resistivity. The calculated RKW of GeNCo3 is 0.286a0 [a0 = 1.0 × 10−5 μΩ·cm/(mJ/mol·K)2].36 This value is smaller than the universal value of a0 for a strong electron correlation system,38 suggesting that GeNCo3 is a weak electron−electron correlation system. Figure 1e presents the temperature dependence of the thermal conductivity κ(T) for GeNCo3 from 5 to 330 K, and κ(T) declines as the temperature decreases. Generally, the total thermal conductivity contains electronic (κe) and lattice (κL) terms; i.e., κtotal(T) = κL(T) + κe(T). We can get κe by using the Wiedemann−Franz (WF) law [κe = (L0T/ρ), where L0 stands for the Lorentz number]. After that, the value of κL can be obtained in terms of κtotal(T) − κe(T). The WF law has been universally approved for a lot of materials.39−41 Here, for antiperovskite nitride GeNCo3, the contributions of κL and κe were divided and plotted versus temperature in Figure 1e. Obviously, the value of κe is smaller than that of κL between 5 and 330 K, suggesting that the magnitude of κtotal(T) is mainly due to the contribution of κL(T). The temperature dependence of the Seebeck coefficient α(T) (between 5 and 330 K) is shown in Figure 1f. Generally speaking, the types of carriers could be determined by the sign of α(T) in a single-band model. In the whole temperature range, the value of α(T) is positive, indicating that hole-type carriers play a major role in GeNCo3. To further prove the experimental result above, we also measured the magnetic field dependence of the Hall resistivity ρxy(H) at 300 K. Accordingly, the result is displayed in the inset of Figure 1f. The Hall coefficient (RH) can be obtained by using the relationship RH = ρxy/H in the singleband model.42 As seen in the inset of Figure 1f, the positive value of RH at high magnetic fields (>10 kOe) is consistent with the result of α(T), confirming that the dominant carriers of GeNCo3 are of the hole type. 3.2. SG Behavior. In order to further investigate the SG behavior in GeNCo3, comprehensive magnetic measurements, such as the field and frequency dependence of ac susceptibility, temperature dependence of dc magnetization at different magnetic fields, and magnetic relaxation, have been carried out and discussed as follows. Figure 2 displays the temperature-dependent dc magnetization M(T) under ZFC and FC processes at 50, 100, 200, 500, 1000, and 5000 Oe for GeNCo3. As the magnetic field increases, the magnitude of magnetization increases, while Tf moves to lower temperatures. According to previous references, Tf in the ZFC curve is resulted from the superparamagnetic blocking of spins.43,44 Also, the shift of Tf is due to the competition between the thermal and anisotropy energy of the particles.43,44 As we know, the increasing applied field will decrease the anisotropy energy of the particles. Thus, less thermal energy will be needed for the particles as the applied magnetic field increases. Finally, Tf moves to lower temperatures. That is to say, large magnetic fields destroy the frozen

Oe under field-cooled (FC) and zero-field-cooled (ZFC) processes between 5 and 300 K. We can find that GeNCo3 undergoes a SG-like behavior, that is to say, an obvious MZFC− MFC irreversibility and a pronounced cusp in the MZFC curve around 51 K (defined as Tf), as indicated by the arrow. A bifurcation like this could be a characteristic of SG behavior, which is similar to those investigated in SnCFe3,6 PdNCr3,9 and GaNMn3.5 Below Tf, the magnitude of MZFC drops steeply to zero, while MFC increases with decreasing temperature, which is another feature of the SG system. In order to characterize this SG state, further measurements were performed, which we will get to later. The inset of Figure 1b shows the isothermal M(H) curves at 5 and 300 K for GeNCo3; both of them show a ferrimagnetic loop. That is to say, the Curie temperature of GeNCo3 is higher than 300 K. We also measured the hightemperature M(T) curve of GeNCo3. However, the paramagnetic state of GeNCo3 is not observed until it decomposes at 657 K, which is confirmed by TGA (see Supporting Information, Figure S1). Figure 1c presents the temperature-dependent resistivity for sample GeNCo3 between 2 and 350 K. Obviously, as the temperature increases, the magnitude of ρ(T) also increases, suggesting an obvious metallic behavior. The low-temperature resistivity (below 30 K) can be fitted by using the equation36 ρ = ρ0 + AT 2

(1) 2

where A represents the T -term coefficient of the resistivity and ρ0 is the residual resistivity. Correspondingly, the values of ρ0 and A are listed in Table 1. The inset of Figure 1c shows a quite good linear fit, indicating that our sample exhibits Fermi-liquid behavior below 30 K. Namely, the electron−electron scatterings play a major role in the resistivity from 2 to 30 K. Figure 1d displays the specific heat CP(T) for GeNCo3 from 5 to 50 K. As can be seen in the inset of Figure 1d, the lowtemperature data (between 2 and 20 K) are plotted as CP(T)/T versus T2, which is fitted well by using the equation36,37 C P(T ) = γT + βT 3 + δT 5

(3)

(2)

where γ represents the electronic specific-heat coefficient, β is the phonon specific-heat coefficient, and δ stands for the coefficient of deviation term.36,37 The values of parameters γ (∼48.42 mJ/mol·K2), β (∼0.3016 mJ/mol·K4), and δ are C

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0.08).47 In general, the relaxation time of the SG behavior near the transition temperature can be expressed by the power law τ = τ0[Tf (f )/T0 − 1]−zv , Tf > T0

(4)

where τ is the relaxation time [τ = 1/(2πf)], τ0 stands for the characteristic flipping time of the magnetic moments, T0 represents the freezing temperature, zv is the dynamical critical exponent, and Tf stands for the frequency dependence of the peak position in χ′(T). On the basis of previous investigations for conventional SG systems, the typical value for zv is in the range of 4−13 and τ0 falls in the range of 10−10−10−13 s. In this study, a best fit using eq 4 gave T0 = 79.43 K, zv = 6.156, and τ0 = 5.0 × 10−12 s (see the inset of Figure 3a), indicating a canonical SG behavior again. Figure 3b presents the real part of the ac susceptibility χ′(T) with frequency f = 50 Hz and ac magnetic field Hac = 3 Oe under different dc magnetic fields (Hdc= 0, 10, 20, and 100 Oe) for GeNCo3. Apparently, the increasing dc field decreases and broadens the magnitudes of the peaks. Tf(H) shifts to lower temperatures as the magnetic field increases. As displayed in the inset of Figure 3b, Tf(H) exhibits a typical H2/3 dependence, which is similar to those of other antiperovskite SG compounds (GaNMn3, SnCFe3, and Cu0.7Ga0.3NMn3)5−7 and the other SG compound Er0.4Sr0.6S.48 Figure 3c shows the isothermal remanent magnetization (MIRM) measured at different magnetic fields at 5 K for GeNCo3. We should note that the sample was cooled to the desired temperature at zero field and then acted on a magnetic field for about 10 min. Subsequently, we measured the remanent magnetization after switching off the magnetic field. The value of MIRM(t) is nonzero even after several hours because of its slow decay, which is another feature of SG behavior.47 The experimental data were fitted according to the formula5−7

Figure 2. M(T) curves for GeNCo3 under ZFC/FC processes with different magnetic fields up to 5 kOe. Note that MZFC and MFC overlap with each other when the magnetic field exceeds 1 kOe.

SG state, and the increasing external field can eliminate the irreversibility. These also coincide well with other SG systems, such as Cu0.7Ga0.3NMn3 and L0.5Sr0.5MnO3 (L = Y, Y0.5Sm0.5, and Y0.5La0.5).7,45 Figure 3a displays the real part of the ac susceptibility χ′(T) for GeNCo3 versus temperature under an ac driving field Hac =

MIRM(t ) = M 0 − α ln(t )

(5)

at various fields up to 10 kOe. The inset of Figure 3c shows the magnetic-field-dependent fitting parameters M0 and α. Like the magnetic field up to 1 kOe, their values initially increase and then saturate. Such a phenomenon can be attributed to the existence of spin frustration and has been observed in other different SG systems.49,50 As mentioned above, the truth of the SG behavior in GeNCo3 has been confirmed, and their detailed characterization has been performed. Now, a question of what is the origin of SG behavior in GeNCo3 comes out. Generally, the existence of SG is closely related with the competitions between antiferromagnetic and ferromagnetic interactions. In many SG systems with antiperovskite structure (GaNMn3, SnCFe3, and PdNCr3),5,6,9 the SG behavior is usually due to deviation of the composition. So, in order to determine the real composition of GeNCo3, measurement of EDS was carried out. Here, it is necessary to point out that the N element is so light that we cannot determine its content accurately by EDS. As a result, the molar ratio of Ge/Co is 0.91:3 (see the right inset of Figure 4), which is less than the stoichiometric ratio of GeNCo3 (1:3), suggesting that a little Ge deficiency exists in our sample. Thus, we infer that the Ge deficiency may be closely associated with the SG behavior. To further confirm our inference, nominal Ge0.9NCo3 with more Ge deficiency was synthesized and corresponding measurements were performed. Figure 4 shows the XRD patterns for the GeNCo3 and Ge0.9NCo3 samples. Obviously, both XRD patterns are indexed to the antiperovskite structure without any impurity. The molar ratio

Figure 3. (a) Temperature dependence of χ′(T) measured at several fixed frequencies for GeNCo3. Inset: Best fit to eq 4. (b) Temperature dependence of χ′(T) at several fixed dc magnetic fields. Inset: Tf plotted as a function of H2/3. (c) Isothermal remanent magnetization (MIRM) for GeNCo3 plotted as a function of time t with H up to 1 kOe. The solid lines are fits to the experimental data according to eq 5. Inset: Magnetic field dependence of the fitting parameters M0 and α.

2 Oe with several different frequencies (f = 1, 10, 100, and 500 Hz). The positions of the peaks move toward to higher temperatures, while the magnitudes of the peaks decrease with increasing frequency, indicating a typical feature in the dynamics of the SG systems.6,46 The relative variation of Tf can be determined from Tf/[TfΔ log10( f)] ∼ 0.01839. This is a typical value for a canonical SG system (between 0.0045 and D

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where T0 = 19.34 K, zv = 10.15, and τ0 = 2.51 × 10−13 s. Furthermore, considering the fact that the origin of the SG state in antiperovskite SG compounds (PdNCr3, GaNMn3, and SnCFe3) and other SG systems (URh2Ge2 and FeAl2) is due to the deviation of stoichiometry,5,6,9,51,52 here, the observed SG in GeNCo3 is probably attributed to the atomic disorder introduced by the Ge deficiencies.

4. CONCLUSION In a word, the sample preparation, crystal structure, thermal transport, magnetism, and electrical transport of the antiperovskite nitride GeNCo3 have been investigated comprehensively. Single-phase GeNCo3 was prepared by a solid−gas method, lattice constant a = 3.6297(5) Å was obtained, Fermiliquid behavior was observed in low-temperature ρ(T), and a weak electron−electron correlation was confirmed by the value of RKW (∼0.286a0). Interestingly, a canonical SG behavior was observed at low temperatures in GeNCo3. After systemic magnetic measurements, the characteristic parameters of the SG such as T0 = 79.43 K, zν = 6.156, and τ0 = 5.0 × 10−12 s were obtained, confirming the truth of the SG behavior in GeNCo3. Furthermore, the nature of the SG in GeNCo3 probably originates from the atomic disorder introduced by the Ge vacancies, which is confirmed by the measurements of nominal Ge0.9NCo3 with more Ge deficiencies.

Figure 4. XRD patterns for GeNCo3 and Ge0.9NCo3 samples. Left inset: Enlarged portion of the reflections (111). Right inset: EDS information on GeNCo3 and Ge0.9NCo3.

of Ge/Co for Ge0.9NCo3 is 0.82:3 (see the right inset of Figure 4), which is less than that of GeNCo3 (0.91:3), meaning more Ge vacancies exist in Ge0.9NCo3. The left inset of Figure 4 exhibits an enlarged portion of the (111) peak, and it shows no obvious shift, meaning that some Co atoms occupy the vacant Ge sites. In this case, atomic disorder existed in nominal Ge0.9NCo3. Figure 5a exhibits dc magnetization M(T) versus temperature for Ge0.9NCo3 under ZFC and FC processes at different

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ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.6b01462. Magnetization and thermogravimetry versus temperature data (PDF)

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AUTHOR INFORMATION

Corresponding Authors

*Tel: +86-551-6559-2757. Fax: +86-551-6559-1434. E-mail: [email protected]. *Tel: +86-551-6559-2757. Fax: +86-551-6559-1434. E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (Grants 51301165 and 51322105), Natural Science Foundation of Anhui Province (Grant 1608085QE107), and Hefei Science Center, CAS (Grant 2015HSC-UP002). Additionally, this work was also supported by the Youth Innovation Promotion Association of CAS (Grant 2014283).

Figure 5. (a) M(T) curves for Ge0.9NCo3 under ZFC/FC processes with different magnetic fields of up to 5 kOe. Inset: Isothermal M(H) curves for Ge0.9NCo3 at 5 and 300 K. (b) Temperature dependence of χ′(T) measured at several fixed frequencies for Ge0.9NCo3. Inset: best fit to eq 4.

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magnetic fields. Apparently, Tf moves to lower temperatures as the magnetic field increases. This is similar to that of nominal GeNCo3 (see Figure 2), indicating that the SG behavior may also happen in Ge0.9NCo3. The inset of Figure 5a presents the M(H) curves for Ge0.9NCo3 at 5 and 300 K, and both of them also show a ferrimagnetic loop. Figure 5b displays the temperature-dependent real part of the ac susceptibility χ′(T) for Ge0.9NCo3 under ac driving field Hac = 2 Oe with several different frequencies (f = 1, 10, 500, and 1000 Hz). By analyzing the data, we note that Ge0.9NCo3 also behaves as canonical SG with parameters of Tf/[TfΔ log10( f)] = 0.0132,

REFERENCES

(1) Yan, J.; Sun, Y.; Wu, H.; Huang, Q. Z.; Wang, C.; Shi, Z. X.; Deng, S. H.; Shi, K. W.; Lu, H. Q.; Chu, L. H. Acta Mater. 2014, 74, 58−65. (2) He, T.; Huang, Q.; Ramirez, A. P.; Wang, Y.; Regan, K. A.; Rogado, N.; Hayward, M. A.; Haas, M. K.; Slusky, J. S.; Inumara, K.; Zandbergen, H. W.; Ong, N. P.; Cava, R. J. Nature (London, U. K.) 2001, 411, 54−56. (3) Wang, B. S.; Tong, P.; Sun, Y. P.; Li, L. J.; Tang, W.; Lu, W. J.; Zhu, X. B.; Yang, Z. R.; Song, W. H. Appl. Phys. Lett. 2009, 95, 222509. E

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Inorganic Chemistry

(37) Goetsch, R. J.; Anand, V. K.; Pandey, A.; Johnston, D. C. Phys. Rev. B: Condens. Matter Mater. Phys. 2012, 85, 054517. (38) Kadowaki, K.; Woods, S. B. Solid State Commun. 1986, 58, 507− 509. (39) Li, S. Y.; Taillefer, L.; Hawthorn, D. G.; Tanatar, M. A.; Paglione, J.; Sutherland, M.; Hill, R. W.; Wang, C. H.; Chen, X. H. Phys. Rev. Lett. 2004, 93, 056401. (40) Hill, R. W.; Proust, G.; Taillefer, L.; Fournier, P.; Greene, R. L. Nature (London, U. K.) 2001, 414, 711−715. (41) Proust, C.; Behnia, K.; Bel, R.; Maude, D.; Vedeneev, S. I. Phys. Rev. B: Condens. Matter Mater. Phys. 2005, 72, 214511. (42) Wang, Z. Z.; Chien, T. R.; Ong, N. P.; Tarascon, J. M.; Wang, E. Phys. Rev. B: Condens. Matter Mater. Phys. 1991, 43, 3020−3025. (43) Sohn, B. H.; Cohen, R. E.; Papaefthymiou, G. C. J. Magn. Magn. Mater. 1998, 182, 216−224. (44) Zhang, L.; Papaefthymiou, G. C.; Ying, J. Y. J. Phys. Chem. B 2001, 105, 7414−7423. (45) Karmakar, S.; Taran, S.; Bose, E.; Chaudhuri, B. K.; Sun, C. P.; Huang, C. L.; Yang, H. D. Phys. Rev. B: Condens. Matter Mater. Phys. 2008, 77, 144409. (46) Feng, W. J.; Li, D.; Ren, W. J.; Li, Y. B.; Li, W. F.; Li, J.; Zhang, Y. Q.; Zhang, Z. D. Phys. Rev. B: Condens. Matter Mater. Phys. 2006, 73, 205105. (47) Mydosh, J. A. Spin Glasses: An Experimental Introduction; Taylor & Francis: London, 1993. (48) Bontemps, N.; Rajchenbach, J.; Chamberlin, R. V.; Orbach, R. Phys. Rev. B: Condens. Matter Mater. Phys. 1984, 30, 6514−6520. (49) Knitter, R. W.; Kouvel, J. S.; Claus, H. J. Magn. Magn. Mater. 1977, 5, 356−359. (50) Aharoni, A.; Wohlfarth, E. P. J. Appl. Phys. 1984, 55, 1664− 1666. (51) Süllow, S.; Nieuwenhuys, G. J.; Menovsky, A. A.; Mydosh, J. A.; Mentink, S. A. M.; Mason, T. E.; Buyers, W. J. L. Phys. Rev. Lett. 1997, 78, 354−357. (52) Lue, C. S.; Ö ner, Y.; Naugle, D. G.; Ross, J. H., Jr. Phys. Rev. B: Condens. Matter Mater. Phys. 2001, 63, 184405.

(4) Kamishima, K.; Goto, T.; Nakagawa, H.; Miura, N.; Ohashi, M.; Mori, N.; Sasaki, T.; Kanomata, T. Phys. Rev. B: Condens. Matter Mater. Phys. 2000, 63, 024426. (5) Song, B.; Jian, J. K.; Bao, H. Q.; Lei, M.; Li, H.; Wang, G.; Xu, Y. P.; Chen, X. L. Appl. Phys. Lett. 2008, 92, 192511. (6) Wang, B. S.; Tong, P.; Sun, Y. P.; Zhu, X. B.; Yang, Z. R.; Song, W. H.; Dai, J. M. Appl. Phys. Lett. 2010, 97, 042508. (7) Zhang, X. H.; Yuan, Q.; Han, J. C.; Zhao, J. G.; Jian, J. K.; Zhang, Z. H.; Song, B. Appl. Phys. Lett. 2013, 103, 022405. (8) Dhar, S.; Brandt, O.; Trampert, A.; Friedland, K. J.; Sun, Y. J.; Ploog, K. H. Phys. Rev. B: Condens. Matter Mater. Phys. 2003, 67, 165205. (9) Lin, S.; Shao, D. F.; Lin, J. C.; Zu, L.; Kan, X. C.; Wang, B. S.; Huang, Y. N.; Song, W. H.; Lu, W. J.; Tong, P.; Sun, Y. P. J. Mater. Chem. C 2015, 3, 5683−5696. (10) Matsunami, D.; Fujita, A.; Takenaka, K.; Kano, M. Nat. Mater. 2014, 14, 73−78. (11) Takenaka, K.; Takagi, H. Appl. Phys. Lett. 2005, 87, 261902. (12) Asano, K.; Koyama, K.; Takenaka, K. Appl. Phys. Lett. 2008, 92, 161909. (13) Lin, S.; Wang, B. S.; Lin, J. C.; Huang, Y. N.; Lu, W. J.; Zhao, B. C.; Tong, P.; Song, W. H.; Sun, Y. P. Appl. Phys. Lett. 2012, 101, 011908. (14) Grandjean, F.; Gerard, A. J. Phys. F: Met. Phys. 1976, 6, 451− 467. (15) Ivanovskii,̌ A. L.; Sabiryanov, R. F.; Skazkin, A. N. Phys. Solid State 1998, 40, 1516−1519. (16) He, B.; Dong, C.; Yang, L. H.; Chen, X. C.; Ge, L. H.; Mu, L. B.; Shi, Y. G. Supercond. Sci. Technol. 2013, 26, 125015. (17) Uehara, M.; Uehara, A.; Kozawa, K.; Yamazaki, T.; Kimishima, Y. Phys. C 2010, 470, S688−S690. (18) Matar, S. F.; Mohn, P.; Demazeau, G.; Siberchicot, B. J. Phys. (Paris) 1988, 49, 1761−1768. (19) Matar, S. F.; Demazeau, G.; Siberchicot, B. IEEE Trans. Magn. 1990, 26, 60−62. (20) Cordier-Robert, C.; Foct, J. Eur. J. Solid State Inorg. Chem. 1992, 29, 39−51. (21) Mohn, P.; Schwarz, K.; Matar, S. F.; Demazeau, G. Phys. Rev. B: Condens. Matter Mater. Phys. 1992, 45, 4000−4007. (22) Kuhnen, C. A.; de Figueiredo, R. S.; Drago, V.; da Silva, E. Z. J. Magn. Magn. Mater. 1992, 111, 95−104. (23) Kuhnen, C. A.; dos Santos, A. V. Solid State Commun. 1993, 85, 273−279. (24) Kuhnen, C. A.; dos Santos, A. V. J. Magn. Magn. Mater. 1994, 130, 353−362. (25) Suzuki, S.; Sakumoto, H.; Minegishi, J.; Omote, V. IEEE Trans. Magn. 1981, 17, 3017−3019. (26) Matar, S. F.; Demazeau, G.; Hagenmuller, P.; Armitage, J. G. M.; Riedi, P. C. Eur. J. Solid State Inorg. Chem. 1989, 26, 517−528. (27) Fruchart, D.; Beataut, E. F. J. Phys. Soc. Jpn. 1978, 44, 781−791. (28) Wiendlocha, B.; Tobola, J.; Kaprzyk, S.; Fruchart, D. J. Alloys Compd. 2007, 442, 289−291. (29) Medkour, Y.; Roumili, A.; Maouche, D.; Maamache, M. Solid State Commun. 2011, 151, 1916−1919. (30) He, B.; Dong, C.; Yang, L. H.; Ge, L. H.; Chen, H. J. Solid State Chem. 2011, 184, 1939−1945. (31) Hui, Z. Z.; Tang, X. W.; Shao, D. F.; Wei, R. H.; Yang, J.; Tong, P.; Song, W. H.; Zhu, X. B.; Sun, Y. P. J. Mater. Chem. C 2015, 3, 4438−4444. (32) Juza, R.; Sachsze, W. Zeitschrift für anorganische und allgemeine Chemie 1943, 251, 201−212. (33) Saegusa, N.; Tsukagoshi, T.; Kita, E.; Tasaki, A. IEEE Trans. Magn. 1983, 19, 1629−1631. (34) Jacobs, H.; Rechenbach, D.; Zachwieja, U. J. Alloys Compd. 1995, 227, 10−17. (35) Stadelmaier, H. H.; Fraker, A. C. Z. Metallkd. 1962, 53, 48−51. (36) Tong, P.; Sun, Y. P.; Zhu, X. B.; Song, W. H. Phys. Rev. B: Condens. Matter Mater. Phys. 2006, 73, 245106. F

DOI: 10.1021/acs.inorgchem.6b01462 Inorg. Chem. XXXX, XXX, XXX−XXX