Unconventional Ferromagnetic Transition in La1-xCaxMnO3

J. W. Lynn; R. W. Erwin; J. A. Borchers; Q. Huang; A. Santoro; J-L. Peng; Z. Y. Li

doi:10.1103/physrevlett.76.4046

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Unconventional Ferromagnetic Transition in La1-xCaxMnO3

J. W. Lynn·R. W. Erwin·J. A. Borchers·Q. Huang·A. Santoro·J-L. Peng·Z. Y. Li

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Abstract

Neutron scattering has been used to study the magnetic correlations and long wavelength spin dynamics of La1-xCaxMnO3 in the ferromagnetic regime (0<=x<1/2). For x=1/3 (Tc=250K) where the magnetoresistance effects are largest the system behaves as an ideal isotropic ferromagnet at low T, with a gapless (<0.04meV) dispersion relation E=Dq^2 and D(T=0)~170 meV-A-1. However, an anomalous strongly-field-dependent diffusive component develops above ~200K and dominates the fluctuation spectrum as T approaches Tc. This component is not present at lower x.

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J. W. Lynn, R. W. Erwin, J. A. Borchers, Q. Huang, A. Santoro, J-L. Peng, Z. Y. Li. 1996-04-29. Unconventional Ferromagnetic Transition in La1-xCaxMnO3. https://doi.org/10.1103/physrevlett.76.4046

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