Tricritical-point phase diagram in PrCuSn.

Tricritical phenomenon appearing in multiple phases is a fundamental and attractive issue in condensed-matter physics. In this work, a field-modulated tricritical phenomenon is realized in single-crystal PrCuSn. The magnetization under variable directions of field indicates strong magnetic anisotropy in PrCuSn, which reveals ferromagnetic coupling for//. A paramagnetic-to-ferromagnetic magnetic transition occurs with//at= 11.7 K, which is evidenced to be of a first-ordered type. The systematical study of the critical behavior gives that= 0.195(8),= 0.911(1), and= 0.0592(1) for//consistent with a tricritical mean-field model, which suggests a field-modulated tricritical phenomenon. A detailed-phase diagram around the tricritical point (TCP) is constructed for single-crystal PrCuSnfor//, where ferromagnetic state, forced ferromagnetic phase and paramagnetic state meet at the TCP (= 799 kOe,= 11.3 K). The single-crystal PrCuSnsupplies a platform to deep investigate the field-modulated magnetic couplings and tricritical phenomenon.