Pressure induced antiferromagnetism in the manganite La0.7Sr0.3Mn0.83Nb0.17O3

The crystal and magnetic structure of a manganite La0.7Sr0.3Mn0.83Nb0.17O3 have been studied by means of a neutron diffraction method at pressures up to 4.5 GPa and in temperature range 4-290 K. At ambient pressure and temperature below T-c = 150 K a ferromagnetic FM state is stabilized in this compound. At pressures P >= 1.5 GPa and temperature below T-N similar to 110 K appearance of a new A-type antiferromagnetic AFM phase in La0.7Sr0.3M0.83Nb0.17O3 has been observed. A further pressure increasing leads to an increase in the volume fraction of the A-type antiferromagnetic AFM phase, which coexists with the suppressed ferromagnetic phase in the whole experimental pressure range. The Curie and Neel temperature increase upon lattice contraction with comparable pressure coefficients dT(C)/dP = 2.1 K/GPa and dT(N)/dP = 1.6 K/GPa. The structural mechanisms of the changes in magnetic structure of La0.7Sr0.3Mn0.83Nb0.17O3 manganite are discussed. (C) 2016 Elsevier B.V. All rights reserved.