TY - JOUR
T1 - Charge and lattice dynamics of ordered state in La1/2Ca 1/2MnO3
T2 - Infrared reflection spectroscopy study
AU - Litvinchuk, A. P.
AU - Iliev, M. N.
AU - Pissas, M.
AU - Chu, C. W.
N1 - Funding Information:
The work at the University of Houston is supported in part by the State of Texas through the Texas Center for Superconductivity and Advanced Materials, NSF grant No. DMR-9804325, the T.L.L. Temple Foundation, the J.J. and R. Moores Endowment. At LBNL we acknowledge the support by the Director, Office of Energy Research, Office of Basic Energy Sciences, Division of Materials Sciences of the US Department of Energy under contract No. DE-AC03-76SF00098.
PY - 2004/11
Y1 - 2004/11
N2 - We report an infrared reflection spectroscopy study of La 1/2Ca1/2MnO3 over a broad frequency range and temperature interval which covers the transitions from the high temperature paramagnetic to ferromagnetic and, upon further cooling, to antiferromagnetic phase. The structural phase transition, accompanied by a ferromagnetic ordering at TC = 234 K, leads to enrichment of the phonon spectrum. A charge ordered antiferromagnetic insulating ground state develops below the Néel transition temperature TN= 163 K. This is evidenced by the formation of charge density waves and opening of a gap with the magnitude of 2Δ0 = (320 ±15) cm-1 in the excitation spectrum. Several of the infrared active phonons are found to exhibit anomalous frequency softening. The experimental data suggest coexistence of ferromagnetic and antiferromangetic phases at low temperatures.
AB - We report an infrared reflection spectroscopy study of La 1/2Ca1/2MnO3 over a broad frequency range and temperature interval which covers the transitions from the high temperature paramagnetic to ferromagnetic and, upon further cooling, to antiferromagnetic phase. The structural phase transition, accompanied by a ferromagnetic ordering at TC = 234 K, leads to enrichment of the phonon spectrum. A charge ordered antiferromagnetic insulating ground state develops below the Néel transition temperature TN= 163 K. This is evidenced by the formation of charge density waves and opening of a gap with the magnitude of 2Δ0 = (320 ±15) cm-1 in the excitation spectrum. Several of the infrared active phonons are found to exhibit anomalous frequency softening. The experimental data suggest coexistence of ferromagnetic and antiferromangetic phases at low temperatures.
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U2 - 10.1016/j.ssc.2004.08.006
DO - 10.1016/j.ssc.2004.08.006
M3 - Article
AN - SCOPUS:4544333960
SN - 0038-1098
VL - 132
SP - 309
EP - 313
JO - Solid State Communications
JF - Solid State Communications
IS - 5
ER -