Effect of Pressure on the Magnetic Properties of Ca1−xSrxMnO3

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Abstract
In order to distinguish among the effects of interatomic distance, B–O–B angle and chemical substitution in perovskites, a study has been made of the variation of Néel points of several samples in the system Ca1−xSrxMnO3 as functions of x and pressure. It is found that throughout the region 0<xTN increases with increasing x, and hence with increasing lattice parameter. However, dTN/dP>0 throughout this region, which indicates just the opposite dependence on cell size. This apparent contradication is compatible with Goodenough's hypothesis regarding the effect of covalence of the nonmagnetic A‐site cation on the magnetic interaction. In addition, it is found that application of hydrostatic pressure reduces the weak ferromagnetic moment. This is most marked at intermediate values of x, where a 25% decrease in moment can be obtained upon application of a hydrostatic pressure of 8 kbar. Increasing x at atmospheric pressure also decreases the weak ferromagnetic moment. These findings indicate that orthorhombic distortion decreases with pressure as well as with x and that variation of the Mn–O–Mn angle influences TN less than variation in chemistry.