Title of article
Resistivity and IR reflectivity of calcium-doped neodymium nickelates
Author/Authors
Zaghrioui، نويسنده , , M. and Poirot، نويسنده , , N. and Monot-Laffez، نويسنده , , I.، نويسنده ,
Issue Information
روزنامه با شماره پیاپی سال 2003
Pages
6
From page
150
To page
155
Abstract
Structural, electrical and IR reflectivity have been investigated for hole doped Nd2−xCaxNiO4+δ. X-ray diffraction has shown that the orthorhombic strain decreases when x increases from 0.05 to 0.33; above the strain increases with x. The dc resistivity indicates a semi-conducting behaviour, which can be described using two conduction modes: a variable-range hopping (VRH) mode at low temperature and a thermically activated mode at high temperature. The temperature of change of conduction mode is function of doping rate. Besides, the thermal resistance of Nd1.67Ca0.33NiO4 compound presents an incident around 200 K, which is attributed to a charge ordering. IR reflectivity does not show any difference in phonon region. But, it exhibits a Mott-Hubbard gap and a difference on plasma frequency depending on x.
Keywords
doping effects , Nickelates , Stripes , Charge ordering , IR reflectivity
Journal title
MATERIALS SCIENCE & ENGINEERING: B
Serial Year
2003
Journal title
MATERIALS SCIENCE & ENGINEERING: B
Record number
2139818
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