Open AccessMagnetic and transport properties of perovskite manganites (La1-xGdx)4/3Sr5/3Mn2O7 (x=0, 0.025) polycrystalline samples
Author(s) -
王治国,
向俊尤,
徐宝,
万素磊,
鲁毅,
张雪峰,
赵建军
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.067501
Subject(s) - condensed matter physics , materials science , tetragonal crystal system , crystallite , doping , ferromagnetism , magnetization , colossal magnetoresistance , lattice constant , perovskite (structure) , electron paramagnetic resonance , magnetoresistance , nuclear magnetic resonance , diffraction , crystal structure , chemistry , magnetic field , crystallography , physics , quantum mechanics , optics , metallurgy
The polycrystalline samples of two-layered perovskite manganites (La1-xGdx)4/3Sr5/3Mn2O7 (x=0, 0.025) are prepared by traditional solid state reaction method. X-ray diffraction measurements show that both samples are of the Sr3Ti2O7 -type tetragonal phase (space groups I4/mmm). Magnetic measurements show that Gd3+ doping reduces the magnetic transition temperature (TC3D) and magnetization (M) of the doped sample (La0.975Gd0.025)4/3Sr5/3Mn2O7, which is because Gd3+ doping induces lattice distortion and change the lattice constant, and subsequently weakens the double exchange interactions. It is found from electron spin resonance measurements that short-range ferromagnetic clusters appear in the paramagnetic background of both samples at temperatures TC3DTTC3DT0.975Gd0.025)4/3Sr5/3Mn2O7 has a higher resistance. This is because Gd3+ doping reduces the localization length of carriers, and makes conducting carriers absorb more energy to overcome the bound potentials in the lattice.