Phase transitions in Sm1-xSrMnO3 single crystals (0≤x≤0.8)

Magnetic and electrical properties of Sm1-xSrxMnO3 (0 less than or equal to x less than or equal to 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 SmMnO3 and for low doped compositions (0 less than or equal to x < 0.05). For 0.4 less than or equal to x less than or equal to 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-er approximate to 193 K, H-er approximate to 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 approximate to 40 K. Below the Neel temperature, a pure antiferromagnetic state without spontaneous magnetization has been observed for 0.5 less than or equal to x less than or equal to 0.575, while for 0.6 less than or equal to x less than or equal to 0.675 an additional low-temperature transition to a new phase with a non-zero weak-ferromagnetic moment has been found.