X-ray metallography by A. Taylor - Crystallography Journals Online

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813
Acta Cryst. (1962). 15, 813
H i s t a m i n e . - - P r e l i m i n a r y X - r a y studies of the crystalline free base. Corrections. B y A. C. A ~ DR~.WS, FRA_~CKDECou, Department of Chemistry, a n d R. D E ~
DRAGSDORF, Department of Physics, Kansas
State University, Manhattan, Kansas, U.S. A
(Received 8 February 1962 and in revised form 9 April 1962)
I n t h e paper b y Andrews et al. (1961) the calculated
d-spacing for t h e 241 planes listed in Table 1 should
be 2.521 A. The l e n g t h of t h e b axis should be one-half
of t h a t given in the paper, i.e., b = 7.64/~. W i t h t h e latter
correction, all k indices should t h e n be one-half those
listed. The u n i t cell has a v o l u m e of 302.8 A 3 a n d contains
two molecules.
I n a d d i t i o n to t h e d a t a p r e s e n t e d in t h e paper, hk0
a n d 0kl precession p h o t o g r a p h s h a v e b e e n m a d e . These
showed systematic absences for 0/c0 w h e n k is odd. The
space group is t h e n P 2 I.
Reference
ANDREWS, A. C., DECoU, F. & DRAGSDORF, R. D. (1961).
Acta Cryst. 14, 1293.
Notes and News
Announcements and other items of crystallographic interest will be published under this heading at the discretion of the
Editorial Board. The notes (in duplicate) should be sent to the General Secretary of the International Union of Crystallography (D. W. Smits, Mathematisch Instituut, University of Groningen, Reitdiepskade 4, Groningen, The Netherlands).
P i t t s b u r g h Diffraction Conference
The annual P i t t s b u r g h Diffraction Conference will be
held on 7, 8 a n d 9 N o v e m b e r 1962 at the Mellon Institute,
Pittsburgh, Pennsylvania. Sessions will be d e v o t e d to ins t r u m e n t a t i o n a n d techniques, structures, metals a n d
alloys, defect lattices and/or radiation damage, w i t h a
special session on X - r a y a n d electron-diffraction microscopy. Professor D a m e K a t h l e e n Lonsdale, F.R.S., of t h e
Chemistry D e p a r t m e n t , U n i v e r s i t y College, London, will
be t h e guest speaker for t h e Thursday evening meeting.
A p l a c e m e n t service will be available. F u r t h e r informat i o n can be o b t a i n e d from W. H. Robinson, Carnegie
I n s t i t u t e of Technology, P i t t s b u r g h 13, Pa., U.S.A.
Book Reviews
Works intended for notice in this column should be sent direct to the Editor (A. J. C. Wilson, Department of Physics, University College, Cathays Park, Cardiff, Great Britain). A s far as practicable books will be reviewed in a country different
from that of publication.
X-ray Metallography. By A. TAYLOr. Pp. VIII
+993.
N e w Y o r k : Wiley. 1961. P r i c e 216s.
There are now several good books deMing w i t h the
application of X - r a y diffraction procedures to metallurgical problems, b u t in 1945 t h e r e were only two
available in English. One of these of course was Barrett,
a n d t h e other was Dr Taylor's ' I n t r o d u c t i o n to X - R a y
Metallography', b a t t e r e d copies of which are still in use
in m a n y metallurgical laboratories. This new book should
t h u s be welcomed in t h e w a y one greets a n old friend,
whose m a n n e r i s m s a n d foibles are already well appreciated. As is to be expected after fifteen years, there are
some signs of middle aged spread, a n d t h e a u t h o r has
h a d to o m i t ' I n t r o d u c t i o n ' from t h e title in view of t h e
993 pages to be f o u n d b e t w e e n t h e covers.
The style a n d general approach of ' X - R a y Metallog r a p h y ' will already be familiar to readers of t h e earlier
book, b u t it should be emphasized t h a t this is a completely
n e w book a n d n o t a revised edition of t h e old. No
knowledge of X - r a y m e t h o d s or of crystallography is
assumed, a n d m o s t results are d e v e l o p e d from first
principles. Metallurgical ideas a n d terminology are also
f r e q u e n t l y p r e s e n t e d ab initio, a n d t h e a u t h o r fulfills
his claim t h a t t h e book is equally suitable for the X - r a y
crystallographer who w a n t s to get a feeling for t h e
metallurgical applications of his techniques. The later
chapters of t h e b o o k describe in considerable detail t h e
ways in which X-rays are used for such diverse purposes
as t h e d e t e r m i n a t i o n of phase diagrams, t h e investigation
of crystal perfection, t h e d e t e r m i n a t i o n of textures, or
t h e s t u d y of phase transformations. I t would be easy to
criticise the w a y in which some of t h e m o r e a d v a n c e d
topics are handled, b u t m o s t unfair to do so. No really
i m p o r t a n t d e v e l o p m e n t seems to h a v e been o m i t t e d ;
selecting almost at r a n d o m , there are descriptions of
X - r a y diffractometry, n e u t r o n diffraction, electron-probe
analysis, t h e focusing techniques of Guinier a n d Termevin
a n d of L a m b e r , Vassamillet a n d Dejace, Lang's m e t h o d
of diffraction mieroradiography, t h e work of W a r r e n
a n d A v e r b a e h on line broadening, a n d descriptions of
n u m e r o u s investigations on stacking faults, short range
order, clustering, etc.
On t h e theoretical side, one feels t h a t the t r e a t m e n t is
a little pedestrian. The reciprocal lattice is i n t r o d u c e d
in a v e r y s k e t c h y m a n n e r , Fourier-transform t h e o r y is
n o t used at all, a n d t h e space which could be spared for
such topics as t h e t h e o r y of dislocations is too brief to
814
BOOK
REVIEWS
m a k e t h e description worthwhile. On t h e other hand,
it is difficult to see w h a t useful purpose is served b y
reproducing s t a n d a r d (112), (111), a n d (110) as well as
(001) projections of cubic crystals, by giving descriptions
w i t h photographs of various types of commercially
available X - r a y e q u i p m e n t , or by including pull-out
charts of ASTM grain sizes. All of these could h a v e been
'included out', as also could perhaps some of the detailed
description of particular experimental investigations,
which has an almost blow by blow aspect at times.
However, these are m i n o r criticisms of a generally well
w r i t t e n a n d informative book. There are several appendices, including some v e r y useful numerical tables.
Department of Metallurgy
Parks Road
Oxford
England
J . W . CHRISTIAN
C o m p u t i n g Methods and the Phase P r o b l e m
in X - r a y Analysis. ( R e p o r t of a Conference H e l d
a t Glasgow, A u g u s t 1960). U n v o l u m e de 326 pages
@dit6 p a r 1%. PEPINSKY, J. M. ROBEI%TSON et J . C.
S P E A ~ N . Oxford, L o n d r e s , N e w - Y o r k , Paris" Perg a m o n Press. 1961. Price 63s.
]:)ix ans apr@s une premi@re rencontre d e n t r6sultat un
ouvrage p o r t a n t le re@me titre que celui-ci, des cristallographes du m o n d e entier se s e n t r@tmis pour discuter
des probl@mes de calcul que soul@ve la d 6 t e r m i n a t i o n
des structures cristallines. Dix ans, c'est long, s u r t o u t
si l'on songe au d@veloppement 'explosif' des calculatrices
m@moires qui se situe duns cet intervalle.
L'ouvrage comporte v i n g t - h u i t contributions dues /~
des sp@cialistes 6minents et se compl@te par les discussions
auxquelles elles ont donn@e lieu. Plus de la moiti@ de ces
contributions se rapporte /~ l'utilisation des machines
@lectroniques, qui s e n t pl@thore.
I1 ne s'agit @videmment pas d ' u n manuel, mais plut6t
d ' u n @chantillonnage spontan6 des pr@occupations qui
a n i m e n t les cristallographes, et c'est 6galement 1/~ qu'il
faut chercher l'int@r6t de ce livre.
Tout ce qui concerne la description des machines k
m6moire, leurs performances et leur utilisation pour
r@soudre les probl@mes 'classiques' (calcul des s@ries de
Fourier et parach@vement des structures) d@route quelque
peu le lecteur par sa surabondance. Que les auteurs des
articles correspondants nous p a r d o n n e n t de ne pas entrer
dans le d@tail de leurs d@veloppements, int@ressants pris
isol6ment. Nous avons n6anmoins appr@ci6, pour notre
part, la discipline de G. A. Jeffrey, R. Shiono et L . H .
J e n s e n (contribution [3]), qui ont condens6 en style
t61@graphique et sous forme de tableau une exp@rience
consid@rable acquise par eux-m@mes et diff@rents autres
chercheurs au pupltre de la 650 IBM.
Mais les cristallographes ach@vent d6jk d ' a d a p t e r au
ealeul 61ectronique leurs besoins t raditionnels et commencent & penser en fonction des nouvelles possibilit@s d e n t
ils disposent. Ainsi ([16] et [27]: A. Niggli, V. V a n d et
R. Pepinsky) la 'm@thode du d@placement optimal',
destin@e ~ compenser le proc@d@ des moindres carr@s
lorsqu'il y a moins d'@quations de condition que d'inconnues, et qui trouve une premi@re application duns une
're@rhode de Monte-Carlo' consist,ant ~ @mettre des
structures arbitraires afin de tendre & se rapprocher de la
structure cherch@e. Mise en programme, par W. Cochran
([22]), de l'~quation dc Sayre (bas@e sur la conviction
- - n o n partag6e par l'auteur de la pr@sente a n a l y s e - que l'utilit6 des relations de signes complipu@es d@cro~t
en raison du n o m b r e des atomes pr@sents dans la maille),
par M. M. V~Toolfson ([23]) d ' u n e modification des @galit@s
de Sayre.
T o u c h a n t au chapitre des machines ~ calculer n o n
universelles, notons une courageuse et pert inente d@fense
de A. Niggli en faveur des dispositifs de calcul '& petite
@chelle' ([3]). Le d i a g r a m m e ternaire pr@tendant lier les
notions de pr@cision, d'@conomie et de maniabilit@ nous
semble c e p e n d a n t plus ing@nieux que logique. E n [4],
description par J. M. Robertson du dispositif m6canique
pour le calcul des s@ries de Fourier qu'il a mis au point
son laboratoire de Glasgow. R. Pepinsky, J. van den
t t e n d e et V. V a n d @crivent /~ propos de l'X-RAC un
article lucide et t o u t & leur h o n n e u r qui fair penser
un @loge fun@bre pour un b e n et loyal serviteur.
C6t@ m@thodes p r o p r e m e n t dites, les techniques 'directes' s e n t d@fendues par E. F. B e r t a u t ([20]: alg@bre des
facteurs de structure lorsque l'on fait varier les vecteurs
de l'espace r@ciproque) et H. H a u p t m a n ([21]: pr6sentation de quelques @galit6s d'application g6n@rale pour la
recherche des signes ou phases des facteurs de structure).
E n mati@re de parach@vements, R. A. Sparks ([17]) expose et compare des diff@rentes fa~ons d'op@rer par
moindres carr@s et d'acc@16rer la convergence.
Les structures complexes et les prot@ines s e n t attaqu@es
par la m 6 t h o d e l ' a t o m e lourd (G. A. Sim, [24]), le reinp l a c e m e n t isomorphe (R. E. Dickerson, J . C . Kendrew,
B. E. Strandberg, [25]), la fonction m i n i m u m de Buerger
(M. G. Rossmann, [26]). Y. Okaya et R. P e p i n s k y pr@s e n t e n t u n d 6 v e l o p p e m e n t rat ionnel pour la r@solution
des structures non eent r@es & l'aide de la dispersion
anomale ([28]).
Pr@sent,ation soign@e, peu d'erreurs, des so~rmaaires qui
facilitent la premi@re lecture: f@licitons le eomit@ d'6dition.
Avee les machines ~ m6moire s'est ouverte pour la
r6solution des structures cristallines une @re nouvelle
pleine de promesses. Sera-t-il vraiment, n6cessaire d'att endre 1970 pour refaire le point ? Esp@rons que non.
Laboratoire de I'IRChA
12 quai Henri I V
Paris I Ve
France
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