doi abstract bibtex

We report an in situ observation of temperature-dependent phase transition in MnAs thin film by transmission electron microscopy (TEM) techniques. Following the identification of the crystallographic transition, from hexagonal alpha-MnAs to quasihexagonal beta-MnAs, the orbital-to-spin moment ratio is measured and a breaking of the ferromagnetic order locally observed, thanks to the electron magnetic chiral dichroism (EMCD) technique. To achieve quantitative information, applying the sum rules to the dichroic signal of magnetic anisotropic materials is accurately discussed. Finally, the orbital-to-spin moment ratio of alpha-MnAs along the easy, hard, and intermediate magnetic axes is estimated by EMCD and compared to implemented density functional theory (DFT) calculations. The influence of the magnetocrystalline anisotropy is locally demonstrated. This work in particular illustrates the feasibility of the EMCD technique for in situ experiments, and proves its potential to explore the anisotropy of magnetic materials.

@article{fu_situ_2016, title = {In situ observation of ferromagnetic order breaking in {MnAs}/{GaAs}(001) and magnetocrystalline anisotropy of alpha-{MnAs} by electron magnetic chiral dichroism}, volume = {93}, doi = {10.1103/PhysRevB.93.104410}, abstract = {We report an in situ observation of temperature-dependent phase transition in MnAs thin film by transmission electron microscopy (TEM) techniques. Following the identification of the crystallographic transition, from hexagonal alpha-MnAs to quasihexagonal beta-MnAs, the orbital-to-spin moment ratio is measured and a breaking of the ferromagnetic order locally observed, thanks to the electron magnetic chiral dichroism (EMCD) technique. To achieve quantitative information, applying the sum rules to the dichroic signal of magnetic anisotropic materials is accurately discussed. Finally, the orbital-to-spin moment ratio of alpha-MnAs along the easy, hard, and intermediate magnetic axes is estimated by EMCD and compared to implemented density functional theory (DFT) calculations. The influence of the magnetocrystalline anisotropy is locally demonstrated. This work in particular illustrates the feasibility of the EMCD technique for in situ experiments, and proves its potential to explore the anisotropy of magnetic materials.}, number = {10}, journal = {Physical Review B}, author = {Fu, X. and Warot-Fonrose, B. and Arras, R. and Seine, G. and Demaille, D. and Eddrief, M. and Etgens, V. and Serin, V.}, month = mar, year = {2016}, note = {WOS:000371960800004}, pages = {104410} }

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