Ferroelectric Soft Mode in Pb(Mg1/3Nb2/3)O3
Abstract
Ferroelectric soft mode in Pb(Mg1/3Nb2/3)O3 (PMN) has been clearly resolved by precision Raman scattering measurements for the first time. A polarization direction of the incident laser was chosen along [110] in cubic configuration in order to eliminate strong scattering components around 45 cm-1, which always smeared the low-frequency spectra of PMN. The soft mode frequency omegas (=omega02-gamma2) softens around 200 K, where omega0 and gamma are a harmonic frequency and a damping constant, respectively. The present result evidenced that the origin of the polarizationthe in PMN is the soft mode.
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