Abstract
We investigate the sensitive interplay between magnetic, electronic, and structural properties in the ferrimagnetic oxide . Emphasis is placed on the impact of reduced dimensionality in the crossover from bulk-like to ultrathin films. We observed an enhanced saturation magnetization for ultrathin films on (001) substrates that co-occurs with a reduced out-of-plane lattice constant under compressive in-plane epitaxial strain. We found a bulk-like cationic coordination of the inverse spinel lattice independent of the film thickness, thus ruling out a cationic inversion that nominally could account for an enhanced . Moreover, our study instead uncovers a reduction of the unit cell volume, i.e., an auxetic behavior in ultrathin films.
- Received 3 November 2014
- Revised 27 January 2015
DOI:https://doi.org/10.1103/PhysRevB.91.054418
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