Magnetic phase transition in La0.8Sr0.2Mn0.9Sb0.1O3 manganite under pressure

The high-pressure evolution of structural and magnetic properties of the single valence Mn3+ manganite La0.8Sr0.2Mn0.9Sb0.1O3 was studied by means of neutron powder diffraction up to 4.5 GPa in the temperature range of 10-300 K. At ambient pressure, a ferromagnetic ground state with the magnetic ordering temperature T-C approximate to 175 K is stabilized. Application of high pressure suppresses the initial FM phase and leads to the appearance of a new A-type antiferromagnetic AFM phase with T-N similar to 130 K at P = 2.2 GPa. Under compression, both T-C and T-N almost linearly increases with the pressure coefficient of 1.9(2) and 0.9(3) K/GPa, respectively. It is assumed that the appearance of the A-type AFM state is mediated by the strong anisotropic distortions of MnO6 octahedra, coupled to the e(g)d(x2-z2) orbital polarization at high pressures.