Experimental Observation of Long-Range Magnetic Order in Icosahedral Quasicrystals

Ryuji Tamura; Asuka Ishikawa; Shintaro Suzuki; Takahiro Kotajima; Yujiro Tanaka; Takehito Seki; Naoya Shibata; Tsunetomo Yamada; Takenori Fujii; Chin-Wei Wang; Maxim Avdeev; Kazuhiro Nawa; Daisuke Okuyama; Taku J Sato

doi:10.1021/jacs.1c09954

Experimental Observation of Long-Range Magnetic Order in Icosahedral Quasicrystals

J Am Chem Soc. 2021 Dec 1;143(47):19938-19944. doi: 10.1021/jacs.1c09954. Epub 2021 Nov 17.

Authors

Affiliations

¹ Department of Materials Science and Technology, Tokyo University of Science, Katsushika, Tokyo 125-8585, Japan.
² Research Institute for Science and Technology, Tokyo University of Science, Katsushika, Tokyo 125-8585, Japan.
³ Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8656, Japan.
⁴ Department of Applied Physics, Tokyo University of Science, Katsushika, Tokyo 125-8585, Japan.
⁵ Cryogenic Research Center, The University of Tokyo, Bunkyo, Tokyo 113-0032, Japan.
⁶ National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
⁷ Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
⁸ School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
⁹ Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan.

Abstract

Quasicrystals (QCs), first discovered in 1984, generally do not exhibit long-range magnetic order. Here, we report on long-range magnetic order in the real icosahedral quasicrystals (i QCs) Au-Ga-Gd and Au-Ga-Tb. The Au₆₅Ga₂₀Gd₁₅ i QC exhibits a ferromagnetic transition at T_C = 23 K, manifested as a sharp anomaly in both magnetic susceptibility and specific heat measurements, along with an appearance of magnetic Bragg peak below T_C. This is the first observation of long-range magnetic order in a real quasicrystal, in contrast to the spin-glass-like behaviors observed for the other magnetic quasicrystals found to date. Moreover, when Gd is replaced by Tb, i.e., for the Au₆₅Ga₂₀Tb₁₅ i QC, a ferromagnetic behavior is still retained with T_C = 16 K. Although the sharp anomaly in the specific heat observed for the Au₆₅Ga₂₀Gd₁₅ i QC becomes broadened upon Tb substitution, neutron diffraction experiments clearly show marked development of magnetic Bragg peaks just below T_C, indicating long-range magnetic order for the Au₆₅Ga₂₀Tb₁₅ i QC also. Our findings can contribute to the further investigation of exotic magnetic orders formed on real quasiperiodic lattices with unprecedented highest global symmetry, i.e., icosahedral symmetry.