Interface effects and the evolution of ferromagnetism in La_2/3Sr_1/3MnO₃ultrathin films

Abstract

Pulse laser deposited La2/3Sr1/3MnO3 ultrathin films on SrTiO3 substrates were characterized by polar and longitudinal Kerr magneto-optical spectroscopy. Experimental data were confronted with theoretical simulations based on the transfer matrix formalism. An excellent agreement was achieved for a 10.7 nm thick film, while a distinction in the Kerr effect amplitudes was obtained for a 5 nm thick film. This demonstrated the suppression of ferromagnetism due to the layer/substrate interface effects. A revised, depth-sensitive theoretical model with monolayer resolution described the experimental data well, and provided clear cross-section information about the evolution of ferromagnetism inside the film. It was found that the full restoration of the double-exchange mechanism, responsible for the ferromagnetic ordering in La2/3Sr1/3MnO3, occurs within the first nine monolayers of the film. Moreover, all the studied films exhibited magneto-optical properties similar to bulk crystals and thick films. This confirmed a fully developed perovskite structure down to 5 nm.

Electronic structure and magneto-optical Kerr effect spectra of ferromagnetic shape-memory Ni-Mn-Ga alloys: Experiment and density functional theory calculations

“…Magneto-optical (MO) spectroscopy in combination with spectroscopic ellipsometry has a great advantage in the investigation of the electronic structure of MFIS materials in comparison with other methods. The MO spectroscopy is very sensitive to the crystal structure and chemical composition [46], valence phase transitions [47], as well as induced strain [48], crystallographic orientation [49], and magnetization direction [50]. Despite many experimental and theoretical studies of electronic and magnetic structures of Ni 2 MnGa compounds, there are quite a few publications devoted to optical and MO Kerr effect (MOKE) spectra of Ni 2 MnGa [51][52][53][54][55][56][57].…”

Electronic structure and magneto-optical Kerr spectra of an epitaxial Ni54.3Mn31.9Sn13.8Heusler alloy film

“…MOKE spectroscopy in combination with spectroscopic ellipsometry has a great advantage in the investigation of the electronic structure of MFIS materials in comparison with other methods. The MOKE spectroscopy is very sensitive to the crystal structure and chemical composition [19], valence phase transitions [20], as well as induced strain [21], crys tallographic orientation [22] and magnetization direction [23,24]. Despite many experimental and theoretical studies of electronic and magnetic structures of Ni-Mn-Sn compounds, there has been no publication devoted to optical and MOKE spectra of these alloys.…”