HIGH PRESSURE NEUTRON DIFFRACTION STUDIES OF RCo_2Si_2 (R : RAREEARTHS) WITH ISING-TYPE LONG PERIOD MODULATED STRUCTURES

ISING型长周期调制结构的RCo_2Si_2（R：稀土）高压中子衍射研究

• 批准号: 05640412
• 负责人: KAWANO Shinji
• 金额: $ 1.28万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640412/
• 关键词: High pressure; Neutron diffraction; Magnetic structure; Phase diagram; PrCo_2Si_2; Erbium; Er; 高圧力; 希土類金属

A high pressure neutron diffraction system has been installed at the B2 beam hole at Kyoto University Reactor (KUR) . It can easily reach a condition of-10K and 3 GPa, combining a clamp-type high pressure cell with a closed cycle refrigerator. Using this system a (P,T) magnetic phase diagram of PrCo_2Si_2 with Ising-type long period modulated structures has established down to 10K up to 2.25 Gpa. Furthermore, the magnetic structures of erbium have been studied under high pressure at low temperatures, where a conical structure at ambient pressure has changed to a cycloidal structure with a modulation of Q=2/7 (2pi/c) having odd harmonics of the c-axis component up to the 7th order.A new cryostat available for the high pressure cell has been designed and fabricated. This cryostat can give a temperature down to 4.2K and moreover, be expected about 2K by pumping liquid helium in a subsidiary tank which is attached to the high pressure cell.

在京都大学反应堆(KUR)的B2束孔安装了高压中子衍射系统。它可以很容易地达到-10K和3 Gpa的条件，结合夹持式高压电池和闭式循环制冷机。利用该系统建立了具有伊辛型长周期调制结构的PrCo_2Si_2的(P，T)磁相图，温度范围从10K到2.25 GPa.此外，还研究了Er在低温高压下的磁结构，其中在常压下的锥形结构变成了调制为q=2/7(2pi/c)的摆线结构，c轴分量的奇次谐波高达7阶。设计并制作了一种可用于高压室的新型低温恒温器。这种低温恒温器可以使温度降至4.2K，此外，通过在连接到高压室的辅助储罐中泵入液氦，预计温度可达2K左右。

项目成果

川野眞治,他: "Magnetic structures of erbium under high pressure" J.Phys.Condens.Matter. 5. 1535-1546 (1993)

Shinji Kawano 等人：“高压下铒的磁性结构”J.Phys.Condens.Matter. 5. 1535-1546 (1993)

川野眞治、他: "Hight pressure neutror diffraction studies of the magnetic structures of erbium" J,Magn.Magn.Materials. 140-144(印刷中). (1995)

Shinji Kawano 等人：“铒磁结构的高压中子衍射研究”J，Magn.Magn.Materials 140-144（出版中）。

S.Kawano et al.: "Magnetic structure of PrCo_2Si_2 under high pressure" Physica B. (in press). (1995)

S.Kawano 等人：“高压下 PrCo_2Si_2 的磁性结构”Physica B.（出版中）。

B.Lebech et al.: "Magnetic structure of erbium under high pressure" Ris phi-R-660 (EN). 19-20 (1993)

B.Lebech 等人：“高压下铒的磁性结构”Ris phi-R-660（EN）。

川野眞治、他: "High pressure neutron diffraction studies of the magnetic structures of Tb,Ho and Er" JAERI-M 93-228. 2. 492-499 (1993)

Shinji Kawano 等人：“Tb、Ho 和 Er 磁结构的高压中子衍射研究”JAERI-M 93-228 (1993)。