Correlation physical property, charge-density-wave and superconductivity in Rare-earth compound crystals which has no inversion symmetry.

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540374
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Okayama University
• Principal Investigator: NOGAMI Yoshio 岡山大学, 自然科学研究科, 教授 (10202251)
• Co-Investigator(Renkei-kenkyūsha): KONDO Ryusuke 岡山大学, 大学院自然科学研究科, 准教授 (60302824)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 電荷密度波 / ４f電子 / 希土類元素 / 磁場 / 磁気秩序

Outline of Final Research Achievements

It was known that SmNiC2 whose crystal structure has no inversion symmetry shows Charge-Density-Wave(CDW) breaking with cooling at Curie Temperature. Interested in this phenomenon, we made single crystals with good quality for many kinds of RNiC2 (R=La, Ce, Pr, Nd, Sm, Gd, Dy, Y, Ho, Er), and measured physical and structural properties. We found two kinds of modulated structures whose wave vector are incommensurate ( 0.5 0.52, 0) and commensurate (0.5 0.5 0.5). Both superstructure were stabilized by lattice parameter shrinkage i. e, the formation temperature of CDW increases with the atomic number. Between Pr and Gd, there is only incommensurate superstructure with resistivity upturn(CDW) and the CDW was destroyed by the external field for at least R=Nd, Sm, Gd. For Dy and Y the competition among two superstructure was observed around room temperature. R=Ho and Er compounds show only the commensurate superlattice above room temperature.

Free Research Field

物理学