Structural, magnetic, and Mössbauer spectral study of the icosahedral quasicrystal Zn77Fe7Sc16

作     者：K. Al-Qadi P. Wang Z. M. Stadnik J. Przewoźnik 

作者机构：Department of Physics University of Ottawa Ottawa Ontario Canada K1N 6N5 Department of Solid State Physics Faculty of Physics and Applied Computer Science AGH University of Science and Technology 30-059 Kraków Poland 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2009年第79卷第22期

页      面：224202-224202页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：freezing ground states iron alloys lattice constants long-range order magnetic susceptibility magnetic transition temperature Mossbauer effect quasicrystals remanence scandium alloys spin glasses zinc alloys 

摘      要：The structural, magnetic, and Mössbauer spectral properties of the icosahedral quasicrystal Zn77Fe7Sc16 are reported. The thermodynamically stable quasicrystal Zn77Fe7Sc16 has a primitive six-dimensional Bravais lattice at room temperature with a six-dimensional hypercubic lattice constant of 7.087(1) Å. Based on dc magnetization measurements, no evidence is found for a transition to a ground state with long-range magnetic order in the temperature range between 2 and 300 K. The dc zero-field-cooled and field-cooled susceptibility data indicate that the studied quasicrystal is a spin glass with freezing temperature Tf=7.75(2) K. This is further confirmed by observing aging effects through the dc zero-field-cooled magnetization and the thermoremanent magnetization time decays and by the analysis of the frequency dependence of Tf using the Vogel-Fulcher law and the dynamic scaling behavior near Tf. However, the observed increase in the thermoremanent magnetization with the magnetic field in the low-field regime is incompatible with the ultrametrically organized phase space of a canonical spin glass. The nature of the spin-glass state of the icosahedral quasicrystal Zn77Fe7Sc16 is therefore fundamentally different from that of a canonical spin glass. The bimodal distribution of the electric quadrupole splitting and of the hyperfine magnetic field derived from Mössbauer spectra indicates the existence of two classes of Fe sites.