Li'an HAN
材料科学技术（英文）
Lattice effect on magnetic and electrical transport properties of Ln2/3Pb1/3MnO3 (Ln=La, Pr, Nd) films prepared by RF magnetron sputtering technique were investigated. With the decrease of the average ions radius , the structure of Ln2/3Pb1/3MnO3 (Ln=La, Pr, Nd) targets transit from the rhombohedral phase to the orthorhombic phase, and the Curie temperature reduces rapidly with the decrease of . The electrical properties show that films are the metallic state which can be fitted to the formula: ρ(T)= ρ0+ρ1T2+ρ2T4.5 at low temperatures. The temperature range of the ferromagnetic metallic state becomes narrow with the decrease of . The phenomenon can be explained by the lattice effect.
关键词:
Lattice effect
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films
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Lattice
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effect
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Magn
Baoxin HUANG
,
Yihua LIU
,
Ruzhen ZHANG
,
Chengjian WANG
,
Gang JI
,
Liangmo MEI
材料科学技术（英文）
The Gd substituting effects for La in La0.67Ca0.33MnO3 has been studied. With increasing the substituting amount of Gd, the phase transition temperature of metal-isolator for the samples decreases, the corresponding peak resistivity increases,the Curie temperature decreases monotonically. The substitution of La-Ca-Mn-O with 11% Gd for La improved the magnetoresistance ratio by an order of magnitude. The effects of substituting Gd can be explained in terms of the lattice effects. An irreversible MR behaviour was observed in Gd-substituting compounds. This effect became marked when the substituting amount of Gd was greater than 7%. A maximum irreversible increment of MR ratio as large as 91% was obtained when Gd substituting amount was 11%.
关键词:
Manganese perovskites
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null
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null
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null
Kexin JIN
材料科学技术（英文）
The transport properties in the La2/3(Ca1-xSrx)1/3MnO3 (x=0, 1/3, 2/3) films prepared using the RF magnetron sputtering method were investigated. The effect of the Ca, Sr double-doping at the $A$ position in the La2/3(Ca1-xSrx)1/3MnO3 on the structure of the targets and transport of the films has been studied. With the increase of x, the structures of the targets transform from the rhombohedral phase to the cubic phase; the metal-insulator phase transition temperature (Tp) of the films increases; and the corresponding peak resistivity decreases. All the phenomena can be qualitatively explained by the lattice effect.
关键词:
Thin films
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null
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null
