Abstract
We study the effect of hydrostatic pressure on the electrical transport, magnetic, and structural properties of by measuring its resistivity, Hall effect, and x-ray diffraction under pressures up to 12.8 GPa supplemented by the first-principles calculations. At ambient pressure, shows a metallic conducting behavior with a cusplike anomaly at around , where it undergoes a long-range antiferromagnetic (AF) transition. With increasing pressure, determined from the resistivity anomaly first increases slightly with a maximum at around 2 GPa and then decreases until vanishing completely at about 7 GPa. Intriguingly, its resistivity is enhanced gradually by pressure and even evolves from metallic to semimetal or semiconductinglike behavior as is suppressed. However, the density of the -type charge carrier that remains dominant under pressure increases with pressure. In addition, the interlayer AF coupling seems to be strengthened under compression, since the critical field for the spin-flop transition to the canted AF state is found to increase with pressure. No structural transition was evidenced up to 12.8 GPa, but some lattice softening was observed at about 2 GPa, signaling the occurrence of an electronic transition or crossover from a localized to itinerant state. We have rationalized these experimental findings by considering the pressure-induced enhancement of antiferromagnetic/ferromagnetic competition and partial delocalization of electrons, which not only destroys long-range AF order but also promotes charge-carrier localization through enhanced spin fluctuations and/or the formation of a hybridization gap at high pressure.
- Received 9 July 2019
DOI:https://doi.org/10.1103/PhysRevMaterials.3.094201
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