Magnetic anisotropy of ferromagnetic La0.7(Sr, Ca)0.3MnO3 epitaxial films

Abstract
The biaxial and uniaxial magnetic anisotropy in epitaxial (100)-oriented La0.7(Sr, Ca)0.3MnO3 films on different substrates were measured by torque magnetometry in the range from T=20 K to room temperature. The biaxial anisotropy with easy axes 〈110〉 dominates and can be described by a cubic crystal anisotropy constant up to K1≈−104 J/m3. A tendency of increasing |K1| with increasing lattice constant c was explained by compressive stress. The uniaxial anisotropy was |KU|⩽103 J/m3 and explained by anisotropic stress not correlated to the crystal axes.