Magnetic transitions and coercive field variations in La1−xSrxMnO3 thin films (0.04 ≤ x ≤ 0.50)

Abstract

We have investigated the electronic and magnetic ground state of La1− xSr xMnO3 thin films, especially around doping x = 0.50 in comparison to the well studied system of x = 0.33 and the low doped system of x = 0.04. The films discussed here were grown by molecular-beam epitaxy, epitaxially strained to (001) oriented strontium titanate substrates. Apart from resistivity and magnetization measurements probing the electronic and magnetic ground state, we also study the temperature dependence of the coercive field of these samples. Our measurements reveal that the coercive field increases as the doping is changed from x = 0.33. The coercive field at 5 K for the x = 0.50 sample is H c = 0.0450 T compared to H c = 0.0080 T for the x = 0.33 sample. The temperature dependent coercive field measurements on the x = 0.50 sample show a dramatic cusp around 100 K that is coincident with more subtle features observed in both magnetization and resistivity data at this temperature.