Magnetic phase transitions in CePtSn

Abstract

Magnetization (M) and specific-heat measurements of a CePtSn single crystal in magnetic fields up to 14 T applied along principal crystallographic axes are reported. CePtSn becomes antiferromagnetic at TN=7.5 K and undergoes an order–order transition at 5 K (in zero field). In a field applied along the a axis (B//a) a metamagnetic transition (MT) is induced that is manifest by a cusp on the M(B) curve at a critical field Bc, an exponential increase of the low-field magnetization, and a linear increase for B>Bc(=12.5 T) at 2 K; Bc decreases with increasing temperature. For B//b, qualitatively different M(B) curves are observed in two temperature regimes. For T<3 K, two MTs are found at 4 and 11 T, respectively, the former one irreversible. For T⩾3 K only the “11 T” transition remains with modified character and Bc is rapidly decreasing with increasing temperature. These MTs are associated with previously reported GMR effects. Microscopic aspects of these phenomena are discussed and updated magnetic-phase diagrams for B//a and B//b, respectively, are presented.

First-order transition under a magnetic ordered state in SmPtSi2

“…C(T) shows a lambda-type anomaly at T H , which is typical for a second-order phase transition whereas it exhibits a sharp peak at T L as expected in case of a first-order transition. The similar temperature dependence in specific heat was observed in CePtSn, along with two-step antiferromagnetic transitions [25]. C(T) on the magnetic field parallel to the b-axis is shown in the inset of figure 1(b).…”

Peculiarities of the magnetic-history-dependent phase in CePtSn

“…3). While lowering the magnetic field, the drop in the magnetostriction is partially (approximately 1 2 ) restored and the subsequent field cycling is almost reversible, with further small but notable features. Also, after first field cycling, the field-induced transition occurs at a significantly lower magnetic field.…”

“…Similar to some CeTX companions, a strong anisotropy of magnetic and other electronic properties is observed in magnetic fields [1]. This compound orders antiferromagnetically (T N = 7.5 K), with subsequent order-to-order transition at T t =5 K (characterized by the appearance of second propagation vector).…”

Magnetoresistance in CePtSn under high hydrostatic pressures

“…At ambient pressure and low temperatures (T < 3 K), two field-induced (AF to AF) transitions are observed for B LF c ∼ 3.5 T and B HF c ∼ 11 T, respectively [1]. Both the transitions are accompanied by pronounced magnetoresistivity steps (−30% and +10%, respectively), however, only with minor features visible on the magnetization curve.…”

“…Similar to some CeTX homologues a strong anisotropy of magnetic and other electronic properties is observed in magnetic fields [1].…”