Schenck A, Gygax F N, Umeo K, Takabatake T, Andreica D
Institute for Particle Physics, ETH Zürich, CH-5232 Villigen PSI, Switzerland.
J Phys Condens Matter. 2006 Feb 15;18(6):1955-66. doi: 10.1088/0953-8984/18/6/011. Epub 2006 Jan 24.
Longitudinal field μSR measurements in applied fields parallel and perpendicular to the c-axis of the hexagonal heavy-fermion antiferromagnet Ce(7)Ni(3) served to monitor the 4f-spin dynamics across the magnetic phase diagram in the B-T plane, which consists of an incommensurate/commensurate antiferromagnetic (AF) section below 1.9 K/0.7 K and below an applied field B of 0.25 T, and for B along the c-axis, of a field-induced magnetic (FIM) section for B≥0.6 T and below 0.5 K. The observed μ(+) spin-lattice relaxation rates reveal persisting spin dynamics across the whole phase diagram, reflect the various phase boundaries and are interpreted to arise in the AF and FIM phases from the Ce3 sublattice (the Ce ions are located on three different sublattices) and in the intermediate phase, viewed as a short range ordered (SRO) state, also from the Ce1 and Ce2 sublattices with slower fluctuation rates. In the paramagnetic regime the Ce1 sublattice displays the slowest spin dynamics. In the FIM phase the fraction of relaxing μ(+) appears to shrink with rising B, evidencing a possible phase separation.
在与六角形重费米子反铁磁体Ce(7)Ni(3)的c轴平行和垂直的外加磁场中进行纵向场μSR测量，以监测B-T平面磁相图上的4f自旋动力学，该相图由低于1.9K/0.7K且低于0.25T外加磁场B时的非公度/公度反铁磁（AF）部分组成，对于沿c轴的B，在B≥0.6T且低于0.5K时为场致磁（FIM）部分。观测到的μ(+)自旋晶格弛豫率揭示了整个相图上持续存在的自旋动力学，反映了各种相界，并被解释为在AF和FIM相中源于Ce3亚晶格（Ce离子位于三个不同的亚晶格上），而在中间相（视为短程有序（SRO）态）中也源于Ce1和Ce2亚晶格，其涨落率较慢。在顺磁区，Ce1亚晶格表现出最慢的自旋动力学。在FIM相中，弛豫的μ(+)的比例似乎随B的增加而缩小，这表明可能存在相分离。
