An NMR study of Pr_{0.5}Ca_{0.5}Mn_{1-x}Ga_xO_3 (x=0 and 0.03)

• Authors: C. Oates , Cz. Kapusta , P. Riedi , M. Sikora , D. Zając , D. Rybicki , C. Martin , C. Yaicle , A. Maignan
• Languages of publication: EN

Abstracts

EN

An NMR study of polycrystalline Pr_{0.5}Ca_{0.5}Mn_{1-x}Ga_xO_3 (x=0 and 0.03) at 3 K is presented. Zero field spin-echo spectra of the Ga doped compound consist of an overlapping ^{69,71}Ga signal at 74~MHz (hyperfine field of 5.3 T), a ^{55}Mn double exchange line at 375 MHz (35.5 T) and a weak Mn^{3+} signal between 400 and 550 MHz. Measurements in an applied field show a step-like increase in the double exchange line intensity, which corresponds to an increase in the amount of the ferromagnetic metallic phase. This coincides with a step-like feature in the bulk magnetization measurements. The effect is similar to that in the previous field dependent ^{55}Mn NMR measurements of Pr_{0.67}Ca _{0.33}MnO_3. At the demagnetized and remanent state, a variation of spin- spin relaxation time, T_2, across the ^{55}Mn line, due to the Suhl-Nakamura interaction is observed, which suggests that the ferromagnetic metallic double exchange regions, at liquid helium temperatures, are at least 4 nm in size.

Keywords

EN

76.60.-k; 75.47.Gk

Discipline

• 76.60.-k: Nuclear magnetic resonance and relaxation(see also 33.25.+k Nuclear resonance and relaxation in atomic and molecular physics and 82.56.-b Nuclear magnetic resonance in physical chemistry and chemical physics; for structure determination using magnetic resonance techniques, see 61.05.Qr; for biophysical applications, see 87.80.Lg; for NMR in superconducting materials, see 74.25.nj)
• 75.47.Gk: Colossal magnetoresistance

• Journal: Acta Physica Polonica A
• Year: 2004
• Volume: 105
• Issue: 1-2
• Pages: 189-195

Dates

published

2004-01/02

received

2003-09-15

Contributors

author

C. Oates

• Department of Solid State Physics, Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow, Poland

author

Cz. Kapusta

• Department of Solid State Physics, Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow, Poland
• School of Physics and Astronomy, University of St. Andrews, St. Andrews, KY16 9SS, Scotland, United Kingdom

author

P. Riedi

• School of Physics and Astronomy, University of St. Andrews, St. Andrews, KY16 9SS, Scotland, United Kingdom

author

M. Sikora

• Department of Solid State Physics, Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow, Poland

author

D. Zając

• Department of Solid State Physics, Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow, Poland

author

D. Rybicki

• Department of Solid State Physics, Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow, Poland

author

C. Martin

• Laboratoire CRISMAT - UMR 6508, ISMRA et Université de Caen, 6 Boulevard du Marechal JUIN, 14050 Caen Cedex, France

author

C. Yaicle

• Laboratoire CRISMAT - UMR 6508, ISMRA et Université de Caen, 6 Boulevard du Marechal JUIN, 14050 Caen Cedex, France

author

A. Maignan

• Laboratoire CRISMAT - UMR 6508, ISMRA et Université de Caen, 6 Boulevard du Marechal JUIN, 14050 Caen Cedex, France

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Identifiers

DOI

10.12693/APhysPolA.105.189