Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505049500
W. Busing, H. G. Smith, S. W. Peterson, H. A. Levy
{"title":"Experience with the Oak Ridge automatic three-circle neutron diffractometer","authors":"W. Busing, H. G. Smith, S. W. Peterson, H. A. Levy","doi":"10.1051/JPHYS:01964002505049500","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505049500","url":null,"abstract":"","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79064948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505052200
A. Murasik, G. Roult
{"title":"Structure magntique du manganite de fer par diffraction neutronique","authors":"A. Murasik, G. Roult","doi":"10.1051/JPHYS:01964002505052200","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505052200","url":null,"abstract":"","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89360554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505048700
R. E. Rundle
Several hydrogen bonds with O-H-O bond lengths of about 2.4 A are now known. Some of these have been examined well enough by neutron diffraction and other means to know with reasonable certainty that they are symmetrical hydrogen bonds, with either a single or a symmetrical double distribution peak. Even neutron diffraction results remain ambiguous as to whether the distribution has a single or double maximum. Several investigators have reported crystallographically symmetrical O-H-O hydrogen bonds with distances of about 2.5 — 2.6 A. Thermal amplitudes of some of these have been given careful study, and most of these longer bonds appear to be truly, not statistically, symmetrical. It seems likely that the bonds of about 2.4 A are distributions with single maxima, while the longer, apparently symmetrical hydrogen bonds are cases of double maxima. IR and NMR evidence that there are O-H-O bonds as long as 2.6 A with single maxima should be carefully checked before they are accepted. From some theoretical calculation of hydrogen distributions in double and single wells it can be shown that cases with double maxima have a strong isotope effect with a shorter O-H-O distance than O-D-O distance, while cases with single maxima should show almost no isotope effect. With present accuracy in structure determinations a distinction between the two cases seems possible with or without the use of neutron diffraction. As an example that bond distances reliable to ~ 0.01 A are now obtainable in nearly routine fashion, the structure of 3, 4-furandicarboxylic acid was determined to about this accuracy with data obtained in ten days.
{"title":"On symmetrical O-H-O hydrogen bonds","authors":"R. E. Rundle","doi":"10.1051/JPHYS:01964002505048700","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505048700","url":null,"abstract":"Several hydrogen bonds with O-H-O bond lengths of about 2.4 A are now known. Some of these have been examined well enough by neutron diffraction and other means to know with reasonable certainty that they are symmetrical hydrogen bonds, with either a single or a symmetrical double distribution peak. Even neutron diffraction results remain ambiguous as to whether the distribution has a single or double maximum. Several investigators have reported crystallographically symmetrical O-H-O hydrogen bonds with distances of about 2.5 — 2.6 A. Thermal amplitudes of some of these have been given careful study, and most of these longer bonds appear to be truly, not statistically, symmetrical. It seems likely that the bonds of about 2.4 A are distributions with single maxima, while the longer, apparently symmetrical hydrogen bonds are cases of double maxima. IR and NMR evidence that there are O-H-O bonds as long as 2.6 A with single maxima should be carefully checked before they are accepted. From some theoretical calculation of hydrogen distributions in double and single wells it can be shown that cases with double maxima have a strong isotope effect with a shorter O-H-O distance than O-D-O distance, while cases with single maxima should show almost no isotope effect. With present accuracy in structure determinations a distinction between the two cases seems possible with or without the use of neutron diffraction. As an example that bond distances reliable to ~ 0.01 A are now obtainable in nearly routine fashion, the structure of 3, 4-furandicarboxylic acid was determined to about this accuracy with data obtained in ten days.","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74779178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505061800
J. Villain
La diffusion des neutrons par les corps magnetiques presente une intensite particulierement grande a la temperature critique a cause des fluctuations d'aimantation importantes qui se produisent alors. On montre que la section efficace critique est proportionnelle a la susceptibilite dans un champ statique sinusoidal, dont on donne des methodes de calcul approche. Lorsqu'on se rapproche des conditions critiques, la diffusion tend a devenir elastique, car la relaxation des fluctuations est freinee par des effets thermodynamiques, et aussi cinematiques dans le cas des ferromagnetiques. On etudie l'inelasticite de la diffusion critique. Les theories faites jusqu'ici reposent sur des hypotheses difficiles a justifier, et ne paraissent pas en accord avec l'experience.
{"title":"Diffusion critique des neutrons","authors":"J. Villain","doi":"10.1051/JPHYS:01964002505061800","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505061800","url":null,"abstract":"La diffusion des neutrons par les corps magnetiques presente une intensite particulierement grande a la temperature critique a cause des fluctuations d'aimantation importantes qui se produisent alors. On montre que la section efficace critique est proportionnelle a la susceptibilite dans un champ statique sinusoidal, dont on donne des methodes de calcul approche. Lorsqu'on se rapproche des conditions critiques, la diffusion tend a devenir elastique, car la relaxation des fluctuations est freinee par des effets thermodynamiques, et aussi cinematiques dans le cas des ferromagnetiques. On etudie l'inelasticite de la diffusion critique. Les theories faites jusqu'ici reposent sur des hypotheses difficiles a justifier, et ne paraissent pas en accord avec l'experience.","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85668219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505047800
C. Cohen-Addad, P. Ducros, A. Durif, E. F. Bertaut, A. Delapalme
{"title":"Détermination de la position des atomes d'hydrogène dans l'hydrogrinat Al2O3, 3CaO, 6H2O par résonance magnétique nucléaire et diffraction neutronique","authors":"C. Cohen-Addad, P. Ducros, A. Durif, E. F. Bertaut, A. Delapalme","doi":"10.1051/JPHYS:01964002505047800","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505047800","url":null,"abstract":"","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75398193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505048400
P. Herpin, P. Mériel
2014 The KHCO3 structure has been resolved by X-rays some years ago, with the exception of the positions of the hydrogen atoms joining two CO3 groups. A single crystal neutron diffraction study has led to precise oxygen parameter values and has allowed us to fix the hydrogen positions. Thé O-H-O bond is asymmetrical and in this structure the linking of the CO3 ions is différent from that observed in sodium bicarbonate : there are (HCO3)2 groups. LE JOURNAL DE PHYSIQUE TOME 25, MAI ’196[1, L’étude aux rayons X [1], [2], [3] ayant conduit à une structure de KHC03 différente des autres sels acides (bicarbonate de sodium, d’ammonium, -sesquicarbonate de sodium), il nous a paru intéressant de déterminer la position des atomes d’hydrogène qui lient les ions CO, par une étude au moyen de la diffraction des neutrons. En même temps, il a été possible de préciser la position des atomes d’oxygène qui, relativement au potassium, diffusent mieux les neutrons que les rayons X. Le bicarbonate de potassium cristallise dans le système monoclinique, sa maille élémentaire a pour dimensions : Elle contient quatre groupements KHC03 et le groupe de symétrie est .P21 ~a. Nous avons utilisé un faisceau de neutrons monocinétiques de longueur d’onde ~ = 1,207 A et nous avons déterminé les intensités de 98 réflexions hk0. Les cristaux étaient taillés en forme de prisme dont la plus grande dimension 10 mm était parallèle à l’axe c. Trois de ces cristaux ont été étudiés ; leurs sections étaient approximativement (1) 4 X 3 mm, (2) 2 X 2 mm et (3) 1 X 1 mm. Sur les courbes de la figure 1 on a porté, en fonction de l’intensité des réflexions mesurées sur le petit cristal (3), les intensités mesurées sur le grand cristal (1) et le cristal moyen (2). Ces courbes montrent que l’effet d’extinction, notable pour le cristal le plus grand, est petit pour le cristal moyen, il doit être négligeable pour le cristal le plus petit. Nous avons pu ainsi nous affranchir de l’extinction. Ilne projection unidimensionnelle (fig. 2) sur Fm. 1. A) Intensités mesurées avec le cristal (1) par rapport au cristal (3). B) Intensités mesurées avec le cristal (2) par rapport ru cristal (3). Frc. 2. -projection unidimensionnelle sur Faxe Ox Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphys:01964002505048400
= =地理= =根据美国人口普查，这个县的土地面积为，其中土地面积为。中子衍射研究has led to A single水晶precision氧气费克斯参数。改良and has allowed us to the硫化氢阵地。O-H-O键是不对称的，在这种结构中，CO3离子的键与碳酸氢钠的键不同:有(HCO3)2个基团。物理日志第25卷,5月’196 [1,X射线研究[1]、[2]、[3]导致KHC03结构不同于其他的酸盐(碳酸氢钠、铵钠-sesquicarbonate),我们发现有趣的氢原子的位置确定CO离子,通过一项有约束力的中子衍射技术。.同时,有人可以澄清,氧原子的相对位置的钾,传播好,中子星的x射线结晶碳酸氢钾单质斜修饰,其网格系统中对于尺寸:它包含了四个KHC03集群和对称性是.P21 ~ a股。我们使用波长~ = 1.207 A的单动力中子束，并确定了98个反射hk0的强度。这些晶体被切割成棱镜的形状，最大尺寸为10毫米，平行于c轴。它们的截面约为(1)4 × 3毫米，(2)2 × 2毫米和(3)1 × 1毫米。曲线上的图1的转发,有人根据实测反射的强度小水晶(3)上的实测强度大水晶(1)和(2)平均灭火。这些曲线显示效果显著,为最多,是小水晶水晶水晶来说微不足道的手段,必须是最小的。因此，我们能够将自己从灭绝中解放出来。Fm. 1上的一维投影(图2)。A)用晶体(1)相对于晶体(3)测量的强度。B)用晶体(2)相对于晶体(3)测量的强度。-一维投影传真Ox文章由EDP科学在线发表，可在http://dx.doi.org/10.1051/jphys:01964002505048400
{"title":"Localisation d'hydrogne et raffinement des positions atomiques dans KHCO3","authors":"P. Herpin, P. Mériel","doi":"10.1051/JPHYS:01964002505048400","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505048400","url":null,"abstract":"2014 The KHCO3 structure has been resolved by X-rays some years ago, with the exception of the positions of the hydrogen atoms joining two CO3 groups. A single crystal neutron diffraction study has led to precise oxygen parameter values and has allowed us to fix the hydrogen positions. Thé O-H-O bond is asymmetrical and in this structure the linking of the CO3 ions is différent from that observed in sodium bicarbonate : there are (HCO3)2 groups. LE JOURNAL DE PHYSIQUE TOME 25, MAI ’196[1, L’étude aux rayons X [1], [2], [3] ayant conduit à une structure de KHC03 différente des autres sels acides (bicarbonate de sodium, d’ammonium, -sesquicarbonate de sodium), il nous a paru intéressant de déterminer la position des atomes d’hydrogène qui lient les ions CO, par une étude au moyen de la diffraction des neutrons. En même temps, il a été possible de préciser la position des atomes d’oxygène qui, relativement au potassium, diffusent mieux les neutrons que les rayons X. Le bicarbonate de potassium cristallise dans le système monoclinique, sa maille élémentaire a pour dimensions : Elle contient quatre groupements KHC03 et le groupe de symétrie est .P21 ~a. Nous avons utilisé un faisceau de neutrons monocinétiques de longueur d’onde ~ = 1,207 A et nous avons déterminé les intensités de 98 réflexions hk0. Les cristaux étaient taillés en forme de prisme dont la plus grande dimension 10 mm était parallèle à l’axe c. Trois de ces cristaux ont été étudiés ; leurs sections étaient approximativement (1) 4 X 3 mm, (2) 2 X 2 mm et (3) 1 X 1 mm. Sur les courbes de la figure 1 on a porté, en fonction de l’intensité des réflexions mesurées sur le petit cristal (3), les intensités mesurées sur le grand cristal (1) et le cristal moyen (2). Ces courbes montrent que l’effet d’extinction, notable pour le cristal le plus grand, est petit pour le cristal moyen, il doit être négligeable pour le cristal le plus petit. Nous avons pu ainsi nous affranchir de l’extinction. Ilne projection unidimensionnelle (fig. 2) sur Fm. 1. A) Intensités mesurées avec le cristal (1) par rapport au cristal (3). B) Intensités mesurées avec le cristal (2) par rapport ru cristal (3). Frc. 2. -projection unidimensionnelle sur Faxe Ox Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphys:01964002505048400","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89063121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505046100
S. Abrahams, K. Knox
{"title":"The hydrogen atom arrangement in ReH2-9","authors":"S. Abrahams, K. Knox","doi":"10.1051/JPHYS:01964002505046100","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505046100","url":null,"abstract":"","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86626396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505052801
N. Menyuk, K. Dwight, A. Wold
Cobalt chromite, CoCr2O4, is a cubic spinel which is ferrimagnetic at low temperatures with a Curie point Tc ≈ 97 °K. The room temperature powder diffraction pattern on this material, corrected for temperature effects, shows that it is a normal spinel with an oxygen parameter equal to 0.38707 :f: .00005. At 4.2 °K there are, in addition to the magnetic contributions to the fundamental spinel peaks, a large number of magnetic 11 satellite " peaks. All of the additional peaks can be indexed on the basis of the ferrimagnetic spiral model proposed for normal cubic spinels by Lyons, Kaplan, Dwight and Menyuk, in which the spiraling components of the spins are defined by a single k vector along a face diagonal. The experimental magnitude of |k| is approximately 5 % greater than theoretically predicted. The neutron diffraction pattern predicted on the basis of the spiral model is completely determined upon fixing the exchange ratio JBB/J AB and the cone axis direction. Taking JBB /J AB = 1. 5 on the basis of magnetization measurements previously reported, it is found that the intensities of the various peaks are in excellent agreement with the intensities predicted by the spiral model with the cone axis along an [001] direction. The ferrimagnetic spiral configuration is known to become unstable relative to small deviations for JBB SB /JAB S A > 0.98 (i.e. JBB/JAB > 0.98 in CoCr2O4). However, our results indicate that the true configuration closely approximates that predicted by the model over a range of exchange interaction ratios which extends well beyond the onset of local instability. Upon increasing the temperature above 4,2 °K, the satellite peaks disappeared between 25 °K and 35 °K, apparently degenerating into a broad plateau observed at 50 °K and 77 °K. Despite this disappearance, a self-consistent fit to neither the magnetic contributions to the fundamental peaks nor the observed thermal variation of the magnetization can be obtained from a collinear model. However, the predicted values based on a molecular field treatment of the spiral model are in good agreement with these measurements. These results further corroborate the validity of the spiral model for CoCr2O4, and indicate that the molecular field approximation accurately describes the axial component throughout its ferrimagnetic range, but not the azimuthal component.
{"title":"Ferrimagnetic spiral configurations in cobalt chromite","authors":"N. Menyuk, K. Dwight, A. Wold","doi":"10.1051/JPHYS:01964002505052801","DOIUrl":"https://doi.org/10.1051/JPHYS:01964002505052801","url":null,"abstract":"Cobalt chromite, CoCr2O4, is a cubic spinel which is ferrimagnetic at low temperatures with a Curie point Tc ≈ 97 °K. The room temperature powder diffraction pattern on this material, corrected for temperature effects, shows that it is a normal spinel with an oxygen parameter equal to 0.38707 :f: .00005. At 4.2 °K there are, in addition to the magnetic contributions to the fundamental spinel peaks, a large number of magnetic 11 satellite \" peaks. All of the additional peaks can be indexed on the basis of the ferrimagnetic spiral model proposed for normal cubic spinels by Lyons, Kaplan, Dwight and Menyuk, in which the spiraling components of the spins are defined by a single k vector along a face diagonal. The experimental magnitude of |k| is approximately 5 % greater than theoretically predicted. The neutron diffraction pattern predicted on the basis of the spiral model is completely determined upon fixing the exchange ratio JBB/J AB and the cone axis direction. Taking JBB /J AB = 1. 5 on the basis of magnetization measurements previously reported, it is found that the intensities of the various peaks are in excellent agreement with the intensities predicted by the spiral model with the cone axis along an [001] direction. The ferrimagnetic spiral configuration is known to become unstable relative to small deviations for JBB SB /JAB S A > 0.98 (i.e. JBB/JAB > 0.98 in CoCr2O4). However, our results indicate that the true configuration closely approximates that predicted by the model over a range of exchange interaction ratios which extends well beyond the onset of local instability. Upon increasing the temperature above 4,2 °K, the satellite peaks disappeared between 25 °K and 35 °K, apparently degenerating into a broad plateau observed at 50 °K and 77 °K. Despite this disappearance, a self-consistent fit to neither the magnetic contributions to the fundamental peaks nor the observed thermal variation of the magnetization can be obtained from a collinear model. However, the predicted values based on a molecular field treatment of the spiral model are in good agreement with these measurements. These results further corroborate the validity of the spiral model for CoCr2O4, and indicate that the molecular field approximation accurately describes the axial component throughout its ferrimagnetic range, but not the azimuthal component.","PeriodicalId":54899,"journal":{"name":"Journal de Physique et le Radium","volume":"146 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1964-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86841418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505049300
M. Doménici
A filter is described which allows the higher harmonics of a " monochromatic " neutron beam to be separated. ’With the aid of this filter one can obtain a very small wavelength which represents the only possibility, with certain apparatus, of exploring the high angle g . LE JOURNAL DE PHYSIQUE TOME 25, MAI 1964, Introduction. -Des filtres d’absorption ont été employés fréquemment en diffraction de neutrons surtout pour éliminer une ou plusieurs composantes d’ordre supérieur dans les études où leur effet de perturbation est particulièrement gênant (ordredésordre, structures magnétiques). Pour des longueurs d’onde principales autour de 1 A, un filtre de plutonium est employé pour éliminer l’harmonique 2. S. C. Abrahams et al. [1], dans une étude sur l’antif erromagnétisme du f er (y), ont employé un filtre de Pu pour éliminer la x J2 et un filtre de Ir pour éliminer À étant de 1,032 À. Dans notre laboratoire, un filtre de Sm, préparé avec 170 mg/cm2 de SM20, en poudre contenue Fie. 1. Section efficace du 149Sm. entre deux feuilles minces d’Al, a été employé pour évaluer exactement le montant de la contamination du second ordre. L’allure [2] de la courbe de la section efficace totale du 149Sm présentée sur la figure 1 est telle, en effet, que les neutrons de longueur d’onde plus grande que 0,9 A peuvent être absorbés tandis que les neutrons de longueur d’onde plus petite que 0,7 A peuvent être transmis. Fie. 2. Comptage sur échantillons de Fe, sans filtres Sm.O.. Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphys:01964002505049300
过滤了歌which is the higher harmonics相称的中子梁to be of A monochromatic”的法门。= =地理= =根据美国人口普查，这个县的面积为，其中土地面积为，其中土地面积为。《物理学报》1964年5月25日，导言。吸收滤光片经常用于中子衍射，特别是在研究中去除一个或多个高阶成分，这些成分的扰动效应特别令人不安(有序无序、磁性结构)。对于1 A左右的主波长，使用钚滤波器来消除谐波2。亚伯拉罕·c . et al[1]上的一项研究中,l’antif erromagnétisme er f (y),使用了一个过滤器,可以消除x J2和过滤器消除由于Ir 3.894过滤器是在我们的实验室里,Sm,准备与SM20 1.7 mg / cm2,奶粉所含的Fie。1。149Sm的有效截面。在两片薄铝箔之间，用来准确评估二阶污染量。如图1所示，149Sm的总截面曲线[2]的路径实际上是这样的，波长大于0.9 A的中子可以被吸收，而波长小于0.7 A的中子可以被传输。五。2。铁样品计数，无Sm.O滤波器。这篇文章由EDP Sciences在线发表，网址为http://dx.doi.org/10.1051/jphys:01964002505049300
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Pub Date : 1964-05-01DOI: 10.1051/JPHYS:01964002505056800
N. Kunitomi, Y. Hamaguchi, S. Anzai
Résumé. 2014 L’étude en diffraction neutronique du tellurure de manganèse, a été faite sur une poudre. L’échantillon soigneusement analysé par rayons X à haute température a été prouvé être exempt de traces de MnO et de MnTe2 qui peuvent contaminer l’échantillon. L’etude a montré que la structure magnétique de MnTe consistait en plans c, ferromagnétiques couplés antiferromagnétiquement suivant l’axe c. La direction des spins est dans le plan c. Le facteur de forme magnétique des ions Mn dans MnTe a été trouvé très proche des valeurs expérimentales déjà données par Corliss et al. La valeur la plus probable du nombre quantique de spin d’après les résultats de la diffraction est 4,6/2 et, d’après les mesures de susceptibilité magnétique 5,05/2. Ceci implique que l’ion manganèse dans MnTe a 5 électrons non appariés. Abstract. 2014 A neutron diffraction study of manganese telluride has been made using powder specimen. The specimen has been carefully checked by high temperature X-ray analysis and has been proved to be free from MnO and MnTe2 which are apt to contaminate the specimen. This investigation has shown that the magnetic structure of MnTe consists of ferromagnetic sheets in c-planes which are coupled antiferromagnetically along the c-axis. The d irection of spins lies within the ferromagnetic sheet. The magnetic form factor of Mn ions in MnTe has been found to be very close to the experimental values obtained by Corliss and others. The most probable value of the spin quantum number is obtained by neutron diffraction data as 4.6/2 and by the measurement of the magnetic susceptibility as 5.05/2. It implies that the maganese ion in MnTe has five unpai- red electrons. Résumé. 2014 Une étude de Fe7Se8 a été entreprise afin de déterminer l’ordre magnétique et les transitions de phase dans ce composé. Sur un échantillon refroidi lentement depuis 600 °C, une surstructure correspondant à la structure 3c trouvée par Okazaki [4] a été mise en évidence. Celle- ci est obtenue à de la maille de en doublant l’axe a et été : Abstract. 2014 An investigation of Fe7Se8 was undertaken to study the magnetic ordering and phase transitions in this compound. On a sample
2014年在粉末上对碲化锰进行了中子衍射研究。经过高温X射线的仔细分析，样品被证明没有MnO和MnTe2的痕迹，这可能会污染样品。研究表明磁结构MnTe是c计划,铁磁性耦合antiferromagnétiquement c轴。旋方向是c计划。磁形状因子中Mn离子MnTe已经找到了与实验值非常接近Corliss的数据等。根据衍射结果，最可能的自旋量子数是4.6 /2，根据磁化率测量，最可能的自旋量子数是5.05 /2。这意味着MnTe中的锰离子有5个未配对的电子。2014年，利用粉末标本对碲化锰进行了中子衍射研究。The样本里都不会用高温的x射线的书analysis and has been to be free from MnO and apt MnTe2 which are to contaminate The样本。= =地理= =根据美国人口普查，这个县的面积为，其中土地面积为，其中土地面积为。= =地理= =根据美国人口普查，这个县的总面积为，其中土地和(3.064平方公里)水。= =地理= =根据美国人口普查，这个县的面积为，其中土地面积为，其中土地面积为。= =地理= =根据美国人口普查，这个县的面积为，其中土地面积为，其中土地面积为。= =地理= =根据美国人口普查，该镇的土地面积为。2014年对Fe7Se8进行了研究，以确定该化合物的磁序和相变。在从600°C缓慢冷却的样品中，突出了与Okazaki[4]发现的3c结构相对应的上部结构。这是通过双轴a和夏季网格获得的:摘要。2014年对Fe7Se8进行了研究，以研究该化合物的磁序和相变。我们有样品
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