Evidences for non-equivalent centers in mixed chain nickelates (NdxY1-x)2BaNiO5

• 作 者: M.V.Narozhnyy S.A.Klimin E.A.Popova G.Dhalenne
• 机 构: Institute of Spectroscopy Russian Academy of Sciences 5, Fizicheskaya Str., Troitsk, Moscow region,
• 出 处: Journal of Rare Earths
• 发表日期: 2009年04期
• 关键词: Haldane chains non-equivalent rare-earth centers Fourier-transform spectroscopy

Absorption spectra of the mixed chain nickelates (NdxY1–x)2BaNiO5 were measured for different x. Experimentally two evidences for the presence of non-equivalent rare-earth centers (NEREC) were found. First, the linewidths show a very strong broadening for x when the calculated distribution over NEREC is wide. Second, a complicated lineshape of the lowest-frequency line in the region of the 4I9/2→4I11/2 electronic transition is in good agreement with statistics of NEREC. A simple modeling for the line broadening due to NEREC is suggested.

Absorption spectra of the mixed chain nickelates (NdxY1-x) 2BaNiO5 were measured for different x. Experimentally two evidences for the presence of non-equivalent rare-earth centers (NEREC) were found. First, the linewidths show a very strong broadening for x when the calculated distribution over NEREC is wide. Second, a complicated lineshape of the lowest-frequency line in the region of the 4I9 / 2 → 4I11 / 2 electronic transition is in good agreement with statistics of NEREC. A simple modeling for the line broadening due to NEREC is suggested.