Pressure-induced changes in transport properties of layered La{sub 1.2}Ca{sub 1.8}Mn{sub 2}O{sub 7}
- Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)
The transport properties of a single crystal of La{sub 1.2}Ca{sub 1.8}Mn{sub 2}O{sub 7} with the layered Sr{sub 3}Ti{sub 2}O{sub 7}-type perovskite structure have been studied under hydrostatic pressures of up to {approximately}9 kbar. It is found that La{sub 1.2}Ca{sub 1.8}Mn{sub 2}O{sub 7} undergoes a first-order phase transition from a paramagnetic insulating to a low-temperature ferromagnetic metallic state which is accompanied by a large decrease in the electrical resistivity. At ambient pressure the magnetic phase transition takes place at T{sub c}=242 K and as the external pressure is applied the critical temperature increases linearly at a rate of 1.1 K/kbar. The present results reflect the competition between double and superexchange resulting from two-dimensional Mn-O-Mn networks and can be interpreted in terms of the exchange striction model. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 553105
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 56, Issue 20; Other Information: PBD: Nov 1997
- Country of Publication:
- United States
- Language:
- English
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