Structural and magnetic ordering in Pr{sub 0.65}(Ca{sub y}Sr{sub 1-y}){sub 0.35}MnO{sub 3} : quantum critical point versus phase segregation scenarios.
The phase diagram of Pr{sub 0.65}(Ca{sub y}Sr{sub 1-y}){sub 0.35}MnO{sub 3}, 0.6{approx}<y{approx}<0.8, has been determined by neutron diffraction, magnetization, and electrical conductivity measurements in order to investigate the nature of the transition between ferromagnetic metallic and charge-ordered insulating states near y=0.75. Two possible scenarios for this transition have been proposed: a 'quantum-critical-point'-like feature, near which an associated charge-disordered paramagnetic phase is present, or a phase coexistence region. We demonstrate that the latter case is true, phase segregation occurring on a mesoscopic macroscopic length scale (several hundred angstroms to several microns). Our results show that no significant amount of the charge-disordered paramagnetic phase is present at low temperatures. Our data also indicate that the charge-ordered insulator to ferromagnetic metal phase boundary is temperature as well as composition dependent.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 949708
- Report Number(s):
- ANL/MSD/JA-43530; PRBMDO; TRN: US1003621
- Journal Information:
- Phys. Rev. B, Vol. 66, Issue Oct. 1, 2002; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- ENGLISH
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