Hidden symmetry of crystal lattices revealed by high-resolution x-ray diffraction

2014 Fiscal Year Final Research Report

• Project/Area Number: 25610100
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: INAMI Toshiya 独立行政法人日本原子力研究開発機構, 原子力科学研究部門 量子ビーム応用研究センター, 研究主幹 (30354989)
• Co-Investigator(Renkei-kenkyūsha): MATSUMURA Takeshi 広島大学, 先端物質科学研究科, 准教授 (00312546) ; MICHIMURA Shinji 埼玉大学, 科学分析支援センター, 助教 (40552310)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 高分解能X線回折 / 多極子秩序 / 電子ネマティック転移 / 量子ビーム

Outline of Final Research Achievements

Lattice deformation, such as thermal expansion and magnetostriction, is an important physical property that describes electronic phase transitions. Although the resolution of dilatometry is very high, those macroscopic measurements observe domain average when a sample deforms from cubic to tetragonal, for instance. In contrast, x-ray diffraction (XRD) distinguishes low-symmetry domains. However, the resolution of XRD on the lattice spacing is not very high. In this experimental study, we employ high-resolution x-ray diffraction (HRXRD), which is a well known technique in x-ray optics. Through measurements on tiny lattice deformations, we discuss the true symmetry of a crystal lattice and nature of an electronic phase transition. In this study, we determined the sign and magnitude of the rhombohedral deformation in phase IV of (CeLa)B6 and discussed quantum fluctuations of the octupole ordered phase. We also discussed the phase transitions of URu2Si2, SmRu4P12 and CeB6.

Free Research Field

磁性