Specific heat of field-dependent magnetic orderings in HoNi2B2C

• Published in: Journal of the Physical Society of Japan 2001-10, Vol.70 (10), p.3037-3041
• Main Authors: CHOI, Jae-Hyuk, DOH, Hyeonjin, CHOI, Eun-Mi, KIM, Heon-Jung, LEE, Sung-Ik, YAMAMOTO, Tatsuharu, KAWAE, Tatsuya, TAKEDA, Kazuyoshi
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties; Magnetic properties and materials; Metals, alloys and compounds (a15, 001c15, laves phases, chevrel phases, borocarbides, etc.); Physics; Properties of type I and type II superconductors; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); Superconducting materials (excluding high-tc compounds); Superconductivity; Ternary, quaternary and multinary compounds (including Chevrel phases, borocarbides etc.)
• ISSN: 0031-9015; 1347-4073
• DOI: 10.1143/JPSJ.70.3037

We have investigated the low-temperature specific heat of HoNi2B2C down to T = 1 K in various magnetic fields from 0 T to 5 T. At zero field, the specific heat exhibits a large peak at TN = 5.1 K, which is due to commensurate antiferromagnetic ordering, and other smaller peak at T1 = 5.5 K, which is related to incommensurate ordering. As the field is increased up to 0.5 T, the first peak broadens and moves to a lower temperature, while the other peak at T1 moves to a higher temperature, which indicates that the phase between TN and T1 is more favored in magnetic fields. Among possible candidates for the phase, the a-axis modulation phase, which is an extension of a low temperature metamagnetic state, is the most probable. In the high-field region above 1 T, the two-peak feature is replaced by a broad-hill one that fades away with increasing fields, which is the typical smearing feature of the magnetic order at high fields.