Phase transitions in Sm_1–xSr_xMnO₃ single crystals (0 ≤ x ≤ 0.8)

Abstract

Magnetic and electrical properties of Sm 1-x Sr x MnO 3 (0 ≤ x ≤ 0.8) single crystals have been studied and the T -x phase diagram has been revised. The compensation points of spontaneous weak ferromagnetic moment have been observed for pure SmMnO 3 and for low doped compositions (0 ≤ x < 0.05). For 0.4 ≤ x ≤ 0.475 the ferromagnetic ordering occurs as a first-order phase transition. It is shown that in a magnetic field the temperature of this transition increases and the transition becomes broader, which results in the appearance of a critical point (T cr ≈ 193 K, H cr ≈ 68 kOe for x = 0.45). Another transition, accompanied by a reduction of magnetization and noticeable anisotropy of magnetization curves, has been observed at low temperature T s ≈ 40 K. Below the Neel temperature, a pure antiferromagnetic state without spontaneous magnetization has been observed for 0.5 ≤ x ≤ 0.575, while for 0.6 ≤ x ≤ 0.675 an additional lowtemperature transition to a new phase with a non-zero weak-ferromagnetic moment has been found.

Multiferroic behaviour in Sm1−xYxMnO3

“…Pure SmMnO 3 is known to exhibit a magnetic transition due to the ordering of the Mn 3+ spins at T N ∼60 K [10]. The Néel temperature measured in our samples shows a drop from this value to ∼48 K for x = 0.4 and ∼46 K for x = 0.5.…”

Tunable spin reorientation transition and magnetocaloric effect in Sm0.7−xLaxSr0.3MnO3 series

“…11,12,29,30,31 Borges et al 18 interpreted that the cusp is due to increase of coercive field with lowering temperature. However, the coercive field of x= 0.6 sample is only 120 Oe even at 10 K, which indicates that the origin of the low temperature anomaly is not due to increase in coercive field.…”

Syntheses, Structure, Magnetism, and Optical Properties of the Ordered Interlanthanide Copper Chalcogenides Ln2YbCuQ5 (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se): Evidence for Unusual Magnetic Ordering in Sm2YbCuS5

“…The abrupt increase of susceptibility data and λ-shape of the jump in the heat capacity at 5.9 K suggest a transition to long range magnetic order with finite magnetic moments aligned to the external field with T c = 5.9 K. This kind of behavior was reported in SmMnO 3 compound, where antiferroamagnetic coupling between weak ferromagnetic Mn ions and paramagnetic Sm ions was ascribed to explain the temperature induced magnetization reversal. 48 Although we don't yet know the details of the magnetic ordering, it seems plausible that a similar situation exists here. In that case, from the temperature dependence of the susceptibility, it is more likely that only one of the ions is ferromagnetically ordered while the other ion is not ordered down to 1.8 K. Regardless, the intriguing temperature dependence at low fields may be understood by antiferromagnetic coupling between the two magnetic ions; one ferromagnetically ordered at below T c while the moment of the other keeps increasing upon cooling.…”