Temperature Dependence of {sup 55}Mn NMR in Pr{sub 0.7}Ca{sub 0.15} Sr{sub 0.15}MnO{sub 3} and Pr{sub 0.7}Ba{sub 0.3} MnO{sub 3} Ferromagnetic Manganites

Journal Article · Sat Nov 01 04:00:00 EST 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.79.4278· OSTI ID:553144

Savosta, M M ^[1]; Novak, P; Jirak, Z; Hejtmanek, J; Marysko, M ^[2]

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1. Donetsk Institute of PhysicsTechnics, Ukraine Academy of Sciences, Rozy Luxembourg 72, 340114 Donetsk (Ukraine)
2. Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 00 Praha 6 (Czech Republic)

The NMR on {sup 55}Mn nuclei was measured in two manganites, which have the same formal valency of Mn and similar Curie temperatures. Pr{sub 0.7}Ca {sub 0.15}Sr {sub 0.15}MnO {sub 3} is metallic below T{sub C} and the spectrum consists of a single, motionally narrowed line. In contrast, in Pr{sub 0.7}Ba {sub 0.3}MnO {sub 3} lines corresponding to localized Mn{sup 3+} and Mn{sup 4+} ions were detected at 77 K. In this compound the increase of temperature leads to an increased rate of electron holes hopping. As a consequence motional narrowing of the NMR spectrum is observed, resulting in a single line for T{gt}140 K . In both compounds the hyperfine fields on {sup 55}Mn nuclei remain finite up to T{sub C} , indicating the first order magnetic transition. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 553144
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 21 Vol. 79; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CALCIUM OXIDES
FERROMAGNETIC MATERIALS
NMR SPECTRA
PEROVSKITES
PHASE TRANSFORMATIONS
PRASEODYMIUM OXIDES
STRONTIUM OXIDES
TEMPERATURE DEPENDENCE