Electronic phase separation in lanthanum manganites: Evidence from {sup 55}Mn NMR

Journal Article · Mon Sep 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.6036· OSTI ID:542236

Allodi, G; De Renzi, R; Guidi, G ^[1]; Licci, F ^[2]; Pieper, M W ^[3]

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1. Dipartimento di Fisica e Istituto Nazionale di Fisica della Materia, Universita di Parma, 43100 Parma (Italy)
2. Istituto MASPEC-CNR, Parma (Italy)
3. Institut fuer Angewandte Physik, Hamburg (Germany)

{sup 55}Mn NMR experiments were carried out at 1.3{endash}4.2 K on six samples of lanthanum manganites, with a hole doping concentration ranging from the antiferromagnetic-insulator to the ferromagnetic-conductor region of the phase diagram. The dependence of the resonance frequencies on external fields is either as expected for ferromagnets (FM) or for antiferromagnets (AF). No indication of a canted phase could be detected. FM and AF resonances were found to coexist in all samples and are grouped in three broad bands, whose frequencies do not depend in first order on hole concentration. Strong evidence of interaction between AF and FM regions was provided by longitudinal relaxation experiments in several samples. An explanation of this behavior is offered in terms of intrinsic phase separation of the holes into FM microdomains. We determine the {sup 55}Mn hyperfine coupling to be isotropic in all cases, with A=6.2T/{mu}{sub B} for the on-site term in the AF domains. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 542236
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 10 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
CALCIUM ADDITIONS
CALCIUM COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL DOPING
FERROMAGNETIC RESONANCE
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MAGNETORESISTANCE
MANGANESE OXIDES
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
PEROVSKITES
PHASE DIAGRAMS
TEMPERATURE RANGE 0000-0013 K