1994 Fiscal Year Final Research Report Summary
HIGH PRESSURE NEUTRON DIFFRACTION STUDIES OF RCo_2Si_2 (R : RAREEARTHS) WITH ISING-TYPE LONG PERIOD MODULATED STRUCTURES
| Project/Area Number |
05640412
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性Ⅱ(磁性・金属・低温)
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KAWANO Shinji RESEARCH REACTOR INSTITUTE,ASSOCIATE PROFESSOR KYOTO UNIV., 原子炉実験所, 助教授 (70027457)
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| Co-Investigator(Kenkyū-buntansha) |
SHIGEOKA Toru CENTER OF INSTR.ANALYSIS,ASSOCIATE PROFESSOR YAMAGUCHI UNIV., 機器分折センター, 助教授 (50167441)
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| Project Period (FY) |
1993 – 1994
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| Keywords | High pressure / Neutron diffraction / Magnetic structure / Phase diagram / PrCo_2Si_2 / Erbium / Er |
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| Research Abstract |
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.
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