Magnetic and dielectric response in spin-lattice coupled system

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400369
• 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: Tokyo University of Science
• Principal Investigator: Mitsuda Setsuo 東京理科大学, 理学部第一部物理学科, 教授 (90183962)
• Co-Investigator(Renkei-kenkyūsha): KITAZAWA HIDEAKI 物質・材料研究機構, 先端材料解析研究拠点, 副拠点長 (00195257) ; NAKAJIMA TARO 理化学研究所, 創発物性科学研究センター, 研究員 (30579785) ; TERADA NORIKI 物質・材料研究機構, 量子ビームユニット, 主任研究員 (60442993)
• Research Collaborator: Karel Prokes Helmholtz-Zentrum Berlin für Materialien und Energie, Department Materials for Green Spintronics ; Klaus Kiefer Helmholtz-Zentrum Berlin für Materialien und Energie, Department Sample Environment
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: スピン格子複合系 / スピンフラストレーション / マルチフェロイック / 交差相関物性 / 一軸応力 / 二等辺三角格子反強磁性

Outline of Final Research Achievements

(i) We have found that the application of uniaxial pressure p up to 600 MPa induces a new ferroelectric phase in a multiferroic CuFe1-xGaxO2, which is different from the well-studied spin-driven ferroelectric phase with helical magnetic ordering. The magnetic structure in the p-induced ferroelectric phase seems to be of a collinear sinusoidal type. Although this magnetic structure itself does not break the inversion symmetry, it is considered to play an important role in the origin of ferroelectricity in the p-induced ferroelectric phase through the spin-lattice coupling in this system. (ii) For an Ising magnet CoNb2O6, we succeeded in crossing the Wannier point (γ = 1) and access the region of γ < 1 by applying uniaxial pressure up to 1GPa along the c axis, where magnetic ground state AF-II magnetic ordering with q=1/ 2 is switched to AF-I magnetic ordering with q=0 at this critical uniaxial pressure~700MPa.

Free Research Field

磁性、中性子散乱