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.

Superconducting and normal-state interlayer exchange coupling inLa0.67Sr0.33MnO3−YSenapati1, Budhani2 2005Phys. Rev. B360350View full textAdd to dashboardCite

“…However, the small value of the switching field suggests that the energy barrier for rotation of magnetization is not large. This result is consistent with the earlier measurements of magnetization loops in films of LSMO deposited on STO substrates 28,29 . The square hysteresis loops seen in the figure further suggest that these films are magnetically quite soft.…”

Raman spectra in epitaxial thin films ofLa1−xCaxMnO3(Xiong1, Chen2, Wang3 et al. 2004Phys. Rev. B502232View full textAdd to dashboardCite

“…The strain can also be caused by the lattice-substrate mismatch 1,19 . This kind of epitaxial strain is different from the strain induced by hydrostatic 20 or chemical pressure 17,18 , since an in-plane strain generally accompanies an out-of-plane strain with different sign, which can cause new electronic behavior did not found in bulk materials of the same chemical composition 1 . The interplay between substrate and film allows the modification of properties and can even enhance the magnetoresistive effect 5,21 .…”

“…One is the rotational-like distortions of the M nO 6 octahedra due to the mismatch between the averaged ionic radii r A of the A-site species and the ionic radius r Mn of Mn. It is one of the strain effects induced by chemical pressure 17,18 . The other is JT distortions of M n 3+ O 6 octahedra.…”

Stoner–Wohlfarth model applied to bicrystal magnetoresistance hysteresis

“…1 are comparable in size when the field is B ≈ K/M . For LSMO films on SrTiO 3 numerical values of K of 1.6 -5.7×10 3 J/m 3 [20,21] have previously been reported. In addition we have M = 400 kAm −1 , as stated above.…”

“…It is known that this kind of tensile strain leads to an in-plane biaxial magnetocrystalline anisotropy in the 110 -directions. [20,21] Hence, this LSMO on SrTiO 3 system can be analyzed with the two-dimensional model considered for the Stoner-Wohlfart theory. The saturation magnetization of the film, determined in a superconducting quantum interference device (SQUID) magnetometer, was 400 kAm −1 .…”