Pressure induced magnetic phase separation in La0.75Ca0.25MnO3 manganite.
The pressure dependence of the Curie temperature T(C)(P) in La(0.75)Ca(0.25)MnO(3) was determined by neutron diffraction up to 8 GPa, and compared with the metallization temperature T(IM)(P) (Postorino et al 2003 Phys. Rev. Lett. 91 175501). The behavior of the two temperatures appears similar over the whole pressure range, suggesting a key role of magnetic double-exchange also in the pressure regime where the superexchange interaction is dominant. The coexistence of antiferromagnetic and ferromagnetic peaks at high pressure and low temperature indicates a phase separated regime which is well reproduced with a dynamical mean-field calculation for a simplified model. A new P-T phase diagram has been proposed on the basis of the whole set of experimental data.
Dipartimento di Fisica, Università Sapienza, Roma, Italy. mbaldini@ciw.edu
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M
Baldini
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Capogna
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Capone
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Arcangeletti
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Petrillo
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Goncharenko
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Postorino