Magnetization Reversal and Glassy Behavior in Tb0.7Sr0.3MnO3

Magnetization reversal and glassy phase in Tb0.7Sr0.3MnO3 are reported. Polycrystalline samples of Tb0.7Sr0.3MnO3 are prepared by solid-state synthesis. This material crystallizes in orthorhombic Pbnm space group with lattice parameters: a = 5.471(1), b = 7.608(2), and c = 5.398(2). Field-cooled/zero field-cooled magnetization measurements show two magnetic transitions, one at 40 K and another at 8 K. The transition at 40 K is due to magnetic ordering of Mn while that at 8 K arises due to Tb ordering. Low field-cooled measurements reveal magnetization reversal at low temperature. The temperature at which this occurs increases with decrease in field strength. The observed magnetization reversal is attributed to the competition between interacting Mn (3 d) and Tb (4 f) magnetic sublattices which makes the system ferrimagnetic. The glassy magnetic behavior below 50 K and absence of long-range order in Tb0.7Sr0.3MnO3 is confirmed through ac susceptibility studies