EPR studies on single crystals of Pr1 - x Pbx MnO3

B. Padmanabhan; Ajay Sharma; S. S. Rao; Suja Elizabeth; H. L. Bhat; S. V. Bhat

doi:10.1016/j.physb.2007.05.002

EPR studies on single crystals of Pr_{1 - x} Pb_x MnO₃

B. Padmanabhan^*, Ajay Sharma, S. S. Rao, Suja Elizabeth, H. L. Bhat, S. V. Bhat

^*Corresponding author for this work

Chemistry

Research output: Contribution to journal › Article › peer-review

3 Scopus citations

Abstract

Electron paramagnetic resonance (EPR) studies are carried out on single crystals of Pr_{1 - x} Pb_x MnO₃, for x = 0.23 and 0.30. The crystal with x = 0.23 undergoes a transition from paramagnetic insulator to ferromagnetic insulator with Curie temperature T_C ∼ 167 K. The crystal with x = 0.30 undergoes a transition from paramagnetic insulator to ferromagnetic metal with T_C ∼ 200 K. The EPR analysis is carried out in the paramagnetic region for both the crystals. The EPR signals are fitted to the Dysonian equation. Linewidth, intensity and asymmetry parameters are plotted as a function of temperature down to T_C. The intensity shows a simple Curie-Weiss behaviour. The spin relaxation takes place through a "bottleneck" mechanism according to which linewidth depends only on strong exchange interaction between Mn^{3 +} and Mn^{4 +} ions. Around 240 K a secondary low field EPR signal is observed for both compositions which persists till around 200 K indicating a possible phase separation.

Original language	English (US)
Pages (from-to)	107-111
Number of pages	5
Journal	Physica B: Condensed Matter
Volume	398
Issue number	1
DOIs	https://doi.org/10.1016/j.physb.2007.05.002
State	Published - Aug 1 2007

Funding

One of the authors (B. Padmanabhan) would like to thank Dr. U.K. Roessler for his valuable comments and suggestions. H.L. Bhat acknowledges CSIR India for financial support.

Keywords

Curie-Weiss law
EPR
Manganites
Phase separation

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Electrical and Electronic Engineering

Access to Document

10.1016/j.physb.2007.05.002

Cite this

@article{260e3ae98a824e6da80085366584f4bb,

title = "EPR studies on single crystals of Pr1 - x Pbx MnO3",

abstract = "Electron paramagnetic resonance (EPR) studies are carried out on single crystals of Pr1 - x Pbx MnO3, for x = 0.23 and 0.30. The crystal with x = 0.23 undergoes a transition from paramagnetic insulator to ferromagnetic insulator with Curie temperature TC ∼ 167 K. The crystal with x = 0.30 undergoes a transition from paramagnetic insulator to ferromagnetic metal with TC ∼ 200 K. The EPR analysis is carried out in the paramagnetic region for both the crystals. The EPR signals are fitted to the Dysonian equation. Linewidth, intensity and asymmetry parameters are plotted as a function of temperature down to TC. The intensity shows a simple Curie-Weiss behaviour. The spin relaxation takes place through a {"}bottleneck{"} mechanism according to which linewidth depends only on strong exchange interaction between Mn3 + and Mn4 + ions. Around 240 K a secondary low field EPR signal is observed for both compositions which persists till around 200 K indicating a possible phase separation.",

keywords = "Curie-Weiss law, EPR, Manganites, Phase separation",

author = "B. Padmanabhan and Ajay Sharma and Rao, {S. S.} and Suja Elizabeth and Bhat, {H. L.} and Bhat, {S. V.}",

note = "Funding Information: One of the authors (B. Padmanabhan) would like to thank Dr. U.K. Roessler for his valuable comments and suggestions. H.L. Bhat acknowledges CSIR India for financial support.",

year = "2007",

month = aug,

day = "1",

doi = "10.1016/j.physb.2007.05.002",

language = "English (US)",

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T1 - EPR studies on single crystals of Pr1 - x Pbx MnO3

AU - Padmanabhan, B.

AU - Sharma, Ajay

AU - Rao, S. S.

AU - Elizabeth, Suja

AU - Bhat, H. L.

AU - Bhat, S. V.

N1 - Funding Information: One of the authors (B. Padmanabhan) would like to thank Dr. U.K. Roessler for his valuable comments and suggestions. H.L. Bhat acknowledges CSIR India for financial support.

PY - 2007/8/1

Y1 - 2007/8/1

N2 - Electron paramagnetic resonance (EPR) studies are carried out on single crystals of Pr1 - x Pbx MnO3, for x = 0.23 and 0.30. The crystal with x = 0.23 undergoes a transition from paramagnetic insulator to ferromagnetic insulator with Curie temperature TC ∼ 167 K. The crystal with x = 0.30 undergoes a transition from paramagnetic insulator to ferromagnetic metal with TC ∼ 200 K. The EPR analysis is carried out in the paramagnetic region for both the crystals. The EPR signals are fitted to the Dysonian equation. Linewidth, intensity and asymmetry parameters are plotted as a function of temperature down to TC. The intensity shows a simple Curie-Weiss behaviour. The spin relaxation takes place through a "bottleneck" mechanism according to which linewidth depends only on strong exchange interaction between Mn3 + and Mn4 + ions. Around 240 K a secondary low field EPR signal is observed for both compositions which persists till around 200 K indicating a possible phase separation.

AB - Electron paramagnetic resonance (EPR) studies are carried out on single crystals of Pr1 - x Pbx MnO3, for x = 0.23 and 0.30. The crystal with x = 0.23 undergoes a transition from paramagnetic insulator to ferromagnetic insulator with Curie temperature TC ∼ 167 K. The crystal with x = 0.30 undergoes a transition from paramagnetic insulator to ferromagnetic metal with TC ∼ 200 K. The EPR analysis is carried out in the paramagnetic region for both the crystals. The EPR signals are fitted to the Dysonian equation. Linewidth, intensity and asymmetry parameters are plotted as a function of temperature down to TC. The intensity shows a simple Curie-Weiss behaviour. The spin relaxation takes place through a "bottleneck" mechanism according to which linewidth depends only on strong exchange interaction between Mn3 + and Mn4 + ions. Around 240 K a secondary low field EPR signal is observed for both compositions which persists till around 200 K indicating a possible phase separation.

KW - Curie-Weiss law

KW - EPR

KW - Manganites

KW - Phase separation

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