Ferrites (Smit, J.; Wijn, H. P. J.)

In this hook the author attempts to re- view exhaustively all instruments for auto- matio or semiautomatic titration which have been described in the ...
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borrow freely from the many excellent problems found a t the end of each chapter. The hook has eonsiders,ble value as a source of references to the original litomture on many topics, and for review study for those reasonably versed in the basic concepts and able to read crit.ically.

Unive~silyof Washington Seattle

Automatic Tihaforr

. I . P. Phillips, University of Louisville,

Lonisville, Kentucky. Academic Press, 225 pp. Inc., New York, 1959. viii Figs. and tables. 16 X 23.5 cm. $6.

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In this hook the author attempts to review exhaustively all instruments for automatio or semiautomatic titration which have been described in the literature or which are available commercially, as of September, 1958. According to the preface, "Automatic titration ie perhaps the only modern inatrumental method of analysis in which the point of view of the ohemist and training in chemistry remain more useful than a n intimate knowledge of physics and electronics. Therefore, the approach used in this hook is that of the chemist. . ." It appears, however, that the reader must have more than a cursory familiarity with electronics to follow some of the descriptions in later chapters. The many instruments discussed are grouped as far as possible according to the method utilized for detection of the end points: potentiometric, amperometric, conductometric, thermometric, and photometric. A chapter is devoted to oaulometric titrators. For each general type, the author gives a brief hut sufficient discumion of the physical chemistry involved followed by a rather detailed description of specific instruments. The descriptions seem rather spotty, with much more detail concerning some models than others; bhis is undoubtedly due in part to the corresponding variety of descriptions in the original sources. There is some repetition; it is difficult to understand why the Beckman KF-2 Aquameter, for example, needs almost identical descriptions on pages 100 and 197. The chief fault as it appears to the present reviewer is the unsatisfactory drawings, in particular those which are not taken directly from the sources. Several of these are a kind of cross between a flowsheet and an eleotronic diagram, so that one has to study carefully to determine whether a solid line represents s burette, a flow of liquid, or a wire. There are a number of questionable statements, only two of which will be mentioned here. On page 10i we find the statement, "Differentiation of a canductometric titration curve gives the shape of the ordinary potentiometrio graph with the end paint near the inflection." Whether or not one likes this use of the phrase, "ordinary potentiometric graph," one must question the truth of the statement,, a t least as applied to an ideal conduetometric titration. Only after reading on ss far as page 130 is this matter clarified.

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Journal of Chemicol Education

Several references are made to the "slow response of most [potentiometric] electrode combinations," which makes necessary complicated end point anticipation circuits; hut, "by contrast with electrodes, most kinds of photaoells have practically instantaneous response." Actually electrode lag is usually less significant than delay due to finite stirring time, and t,his will be present equally far all types of detection. In spite of its shortcomings, this hook should fill a need as a convenient compilation of data. from many sources, as all chapters are well documented. The printing and binding leave nothing to he desired. The reviewer only found two minor typographical errors.

GALENW. EWING New Mezieo Highlands University Las Vegm, New Mezieo

Qualitative Analysis and Electrolytic Solutions

Edward J. King, Barnard College, Columbia University, New York. Haoourt, Brace and Co., New York, 1959. xxi 641 pp. Many figs. and tables. 16.5 X 23.5 em. $6.95.

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The appearance of still another textbook of qualitative analysis ordinarily evokes little more than a casual oomment from those of us engaged in the teaching of this aspect of chemistry. Most "new" texts contain little that is new, and modern versions of alder yet reliable volumes are often less desirable. King's recent work, however, is one which deserves special consideration. The text is designed either for a, sophomore course or for the seoond semester of

tory practice of qualitative analysis is covered in the second half. The structure of water and of ~olutesare considered as well as their interaction to form solutions. Bonding is treated primari1.v from an eleetroststic point of view and a brief excursion is made into ligand field theory. Rates and equilibrium are excellently covered. The effects of interionic forces are carefully considered and the principles of eleetroneutrality and of material balance are introduced to aid the student in understanding the assumptions usually made in solving simple equilibrium prohlema as well ss to provide the foundation necessary for mlving more complex prohlems. Sufficient depth of material is included so that a. very complete and rigorous treatment of the principles of eleotrolytic solution chemistry can he given s t the discretion of the instructor. Each chapter contains pertinent references to the original literature, sopplementaryrending8,and anumher of problems designed to encourage the student to think rather than to substitute blindly into equations derived in the text. Many examples, however, of more dificult types of problems are worked out in detail in the text and answers to numerical problems are given in the appendix. The laboratory part of the book is based on s. oonventional qualitative scheme of

analysis, but one in which thioacotamide is used instead of hydrogen sulfide. The author points out the objections many have raised to the substitution of thioacetamide far hydrogen sulfide hut also emphasizes that tho study of the mechanism of sulfide precipitations with thioacetamide is one of the frontiers of chemistry. By ut.ilizing the most r ~ c m t~ t n d i e sas examples of kinetics and hgmogeneous precipitation the author illustrates the current interest in problems which the student may himself encounter in the laboratory. The text does include, however, the slight modifications in procedure necessary if one wishes to use hydrogen sulfide. The laboratory section also contains an extensive discussion of the chemistry of the elements included in the qualitative scheme based on structural considerations, electrode potentials and equilibrium constants. For each analytical group cross references are made to those sections in the first part of the text which are helpful in understanding the descriptive chemistry of the individual elements. The author has produced a thoroughly up-to-date text which calls attention to the frontiers of chemistry. The book is extremely well written and deserves the attention of everyone interested in a current approach to the teaching of qualitative analysis and the attendent principles governing the behavior of electrolytic solutions. ROYA. WHITEKER Haruey Mudd College Clawmont, California Ferriter

J . Smit and H . P . J. Wijn, both of Philips Research Laboratories, Eindhoven, The Netherlands. John Wiley & Sons, New York, 1959. xiv 369 pp. Figs. and tables. 15.5 x 23.5 cm. $10.

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Before commenting on the merits of this hook, i t might he helpful to cite a few facts gleaned from the hook t o explain the title. Femites are defined as magnetic oxides containing iron as the major constituent.. They are typified by magnetite, the well-knorvn ferromagnetic iron oxide, Fe804, and the related spinels, MeFe.04, where Ale is one of the divalent ions of the transition elements, Mn, Co, Ni, Cu, and Zn, or Mg and Cd. Another large clms of ferrites is derived from ternary mixtures of BaO and Fe.0, with MeO, where Me again represents divalent, transition-element ions, or Zn, Mg, or a combination of Li' and Fen'. Crystals based upon the formula YsFesOLn, having a garnet strurtxre, are also ferromagnetic; the yttrium ion can he replaced by those of rare-earth metals, because af nearly identical ionic radii. The replacement of one ion by another in these structures need not he stoiehiometric, resulting in compounds with strange looking formulas, like: Nit,, Zno.&e104; Ba3Col.prFe"o.osFe,10e; and BaCo.~~Zn0.~,Fe,..s01r.These compounds frequently have vacant lattice sites and the porosity remaining during their preparation also affects their properties. The (Continued on page A4.94)

BOOK REVIEWS a r t of producing ferrites, thus, is one of varying the composition and the processing variables to obtain the desired combination of properties. They are made by sintering well-mixed, finely-divided oxides, carbonates, or other mitable compounds. The magnetic perticlos are oriented by a magnetic fiold during compaction while in t.he mold to form a "green" compact. The orientation persists during the sintering operation to a greater or less degree, depending upon the temperature, the sintering atmosphere, and other factors. Rather than a book for chemists or ceramists, klling how to make ferrites, the authors present the physics of magnetism and theories concerning the origin of magnetism in ferrites. Besides diamagnetism, paramenetism, and ferromagnet,ism, words t,hat are generally

familiar to chemists, we now encounter ferrimagnetism, antiferromagnetism, remanent magnetism, internal demagnetization, magnetostatic mode, and other new concepts. The ingenuity with which the properties have been related to crystal structure and orimtatian of the various ions is admirahle and well documented. I t is shown that there are three different ways of learning about the distribution of the ions among the available crystal sites in such magnetic eompounds, namely, use of X-ray diffrsction and neutron diffraction and hy a. determination of the magnitude of the saturation magnetization a t zero degrees Kelvin. One of the chief uses of neutrons in crystal stn~cturcanalysis has been in this field. While the authors use physical models rather than following a mathemat,iexl approach, and in spite of the fart that, they

claim that this book treats ferrites on s n "intermediate" level, it is not one for the novice. Pior is it a hook for the engineer who wishes to take advantage of the widely varying magnetic properties of ferrites in designing new electronic eircuits. Rather it will b e d serve the needs of the p h r ~ i c a l chemist who wants to understand the properties of these extraordinary compounds as related to theircrystallinestruct~treandconstitution. LAURENCE S. FOSTER

Waterlotun Arsenal Waledown, Massachusetts

Exploring the Structure of Mower

JeanJacpues Trillnl, Professor a t the Sorbonne and Director of the X-Ray Laboratories, French National Centre for Scientific Research. Translated by F. W . Kent. Interscience Publishers, Inc., New York, 1959. 214 pp. 9% figs., 23 plates. 15 X 22 cm. $4.85. This book deals with the fundamental principles of microradiography by X-rays and electrons, elcctran microscopy, and clectron and neutron diffraction, and r i t h their application to a wide variety of problems in physics, chemistry, metallurgy, hiology, and related areas. Only a general familiarity of the reader ufth the fundamental principles of atomic physics is assumed. 1)erivations and explanations are straightforward and the text is nicely supplemcntod with numerous diagrams and photographs. Samo advanced topics are also included, notably a discussion of Rikuehi line phenomena. The volume offers to the novice a good survey of the subject matter mentioned earlier, and is also of use to workers in the field. Unfortunately, there are several defects which detract from the treabment. The book suffers in translation; phrases such as "The surface u4l berame the seat of a secondary diffusion. . . " (p. 30), "In this province of light alloys. . . " (p. 100), ". . .euperfirial atoms. . . " (p. 1491, show too great a n adherence to the elegnnee of tho original French text. Of grcnter consoquenre are mist,ranslations in scientific terminology such RS "SUTstrrwtrm rays" (p. 150) for mprr8t,nleture lines, the unfortnnate use of the phrase "diffusion of X-rays" (p. 120) when scattering is meant, and the statement that a radiation produced hy neutron bomhardment of 8 ' is "vigorously ionized" ( p 190). The reviewer also objects to statements such as: . . " T h e minute structure of matter calls for the investigation [ d l processes which, in most cases, involve radiations which have wave form (light, X-rays, ultraviolet ar infrared rays, etc.) or c o r p u ~ ~ u l aform r (electrons, elementary pnrt,ieles). . ."(p. 1 or ' , X-ray? are elretromagnetic waves, whilst electrons are material particles having a ~tranglymarked dual character, cnrposculxr and undulatory, that is to say, material corpuscles grtidd hy 'waves of probshility' " (p. 120). In a hook offering experimental proof of the inadcqnaey of "particle" and "wave" ( C o n t i w e d on page .4456)

A434

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Journal of Chemical Education