Successive Magnetic Phase Transitions of Component Orderings in DyB4

Matsumura Takeshi

Okuyama Daisuke

Mouri Takuya

Murakami Youichi

Journal of the Physical Society of Japan

The successive magnetic phase transitions in DyB4 have been studied in detail by microscopic measurements using resonant X-ray diffraction and neutron scattering. It is shown that the ab-plane component of the magnetic moment is short-range-ordered in the intermediate phase where the c-axis component is long-range-ordered. It is estimated that this short-range order is dynamically fluctuating with a time scale between ~ 10−8 to ~ 10−11s. Crystal field excitation has also been investigated by inelastic neutron scattering. To qualitatively understand the phase-transition phenomenon, we have studied a simple two-sublattice model with an antiferromagnetic interaction by mean-field calculation. The calculation, though without a quadrupolar interaction, successfully explains the occurrence of double phase transition, magnetic specific heat and entropy, magnetic susceptibility, and the huge elastic softening in the intermediate phase. The general success of the mean-field calculation, except for the shortrange order, suggests that there is little effect of geometrical frustration on the macroscopic properties at zero magnetic field.

DyB4

successive magnetic transitions

component ordering

geometrical frustration

物理学 [ 420 ]

英語

The Physical Society of Japan

一般社団法人日本物理学会

Copyright (c) 2011 The Physical Society of Japan

Copyright (c) 2011 一般社団法人日本物理学会

This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。

[ISSN] 0031-9015

[NCID] AA00704814

[DOI] 10.1143/JPSJ.80.074701

[DOI] http://dx.doi.org/10.1143/JPSJ.80.074701