Atomic scale insight into strain induced ferromagnetism at the interface of SrCrO 3 -SrTiO 3 nanocomposite

Abstract

This study systematically investigates the structural evolution and magnetic property regulation mechanisms of the SrCrO 3 -SrTiO 3 nanocomposite system. X-ray diffraction analysis combined with Rietveld refinement results indicate that as the SrTiO 3 doping concentration increases, the material maintains a single perovskite phase structure, with the intensity of the SrTiO 3 (110) characteristic peak significantly enhanced and the half-width narrowed, confirming the formation of a continuous nanocomposite. Detailed structural refinement revealed SrTiO 3 -induced lattice anisotropic strain characteristics, with the c/a ratio increasing from 1.001 to 1.042, while CrO 6 octahedra undergo significant distortion along the c-axis. Magnetic property tests show that the material transitions from the antiferromagnetic properties of pure SrCrO 3 to distinct ferromagnetic properties, with the x = 0.3 sample exhibiting the most outstanding magnetic properties, including a saturation magnetization of 0.094 emu/g, a coercivity of 1100 Oe. First-principles calculations were conducted to thoroughly analyze the evolution of the electronic structure, revealing a shift of electronic states from the SrTiO 3 region to the SrCrO 3 region, significantly enhancing interfacial orbital hybridization. Spin charge density analysis indicates that the spin density in the nanocomposite interface region is significantly enhanced. This is attributed to the synergistic effects of interfacial orbital hybridization, lattice strain-induced Cr 3d orbital energy level restructuring, and interface oxygen vacancies, as revealed by our combined experimental and computational analyses. The experimental observations are in excellent agreement with theoretical calculations, establishing a comprehensive structure-property relationship model from atomic-scale electronic structure to macroscopic magnetic properties.