Structure-properties phase diagram for La{sub 1-x}Sr{x}MnO{sub 3} (0.1{le}x{le}0.2).
By combining the results of magnetization, resistivity, and neutron powder-diffraction data for stoichiometric La{sub 1-x}Sr{sub x}MnO{sub 3}, we have constructed a phase diagram that describes the magnetic, transport, and structural properties and the relationships among them as a function of composition (0.1{<=}x{<=}0.2) and temperature (10-340 K). We show that, with increasing Sr content, the Curie temperature increases linearly, while the temperature of an orbital ordering transition to a state with a large coherent Jahn-Teller (JT) distortion decreases. These two phase-transition lines cross at x=0.145 and T=210 K. When the transition to the ferromagnetic state occurs in a phase that has a large coherent JT distortion (x<0.145), a strong magnetolattice coupling is observed; the coherent JT distortion is dramatically reduced and the incoherent distortion is enhanced in the ferromagnetic phase. For x>0.145, where the coherent JT distortion is small above Curie temperature, magnetolattice coupling reduces the incoherent distortion at T{sub c} and strongly suppresses the transition to a phase with a large coherent JT distortion. These observations are consistent with a competition between ferromagnetism and JT distortion that is mediated by a colossal spin-charge-lattice coupling. A metallic state occurs below the Curie temperature when both coherent and incoherent JT distortions are suppressed.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); USDOD
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 942759
- Report Number(s):
- ANL/MSD/JA-34314; TRN: US0904223
- Journal Information:
- Phys. Rev. B, Vol. 60, Issue 10 ; Sep. 1, 1999; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- ENGLISH
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