From ferro- to antiferromagnetism via exchange-striction of MnAs/GaAs(001)
We investigated the stress evolution in single-crystal MnAs films on GaAs(001) upon applying high external magnetic fields in the α/β phase transition regime (10-40 °C) and beyond. Our stress measurements reveal large field-induced lattice distortions at temperatures, where β-MnAs is present, even w...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2005
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| Summary: | We investigated the stress evolution in single-crystal MnAs films on GaAs(001) upon applying high external magnetic fields in the α/β phase transition regime (10-40 °C) and beyond. Our stress measurements reveal large field-induced lattice distortions at temperatures, where β-MnAs is present, even well above the phase transition (> 40 °C). A quantitative comparison with the field-induced increase of magnetization reveals that the changes in the lattice dimensions can be fully explained by the (reversible) back-transformation of β-MnAs to α-MnAs. Our direction-dependent experiments identify the structural distortions at the phase transition as a volume magnetostriction effect and - due to the persisting magnetocrystalline anisotropy above 40 °C - strongly support an antiferromagnetic state for β-MnAs. © EDP Sciences. |
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