Structural Characterization and Magnetic and Electrical Properties of La0.7Ca0.3MnO3-La1.5Sr0.5NiO4 Nanocomposites

作者：Tran Dang Thanh^*; Hoang Thanh Van; The Long Phan; Seong Cho Yu

来源：Journal of Electronic Materials, 2014, 43(4): 1083-1090.

DOI：10.1007/s11664-014-3009-5

• Nanocomposites
• perovskite manganites
• electrical and magnetic properties

Nanocomposite samples of (1 - x)La0.7Ca0.3MnO3 + xLa(1.5)Sr(0.5)NiO(4) (x = 0 to 0.3) were synthesized by a combination of the mechanical milling and solid-state reaction methods. X-ray diffraction analyses and magnetic measurements indicated that no reaction occurred between La0.7Ca0.3MnO3 (LCMO) and La1.5Sr0.5NiO4 (LSNO). The Curie temperature (T (C)) was almost independent of x, while the metal-insulator transition temperature (T (MI)) shifted from 251 K for x = 0.0 to 65 K for x = 0.2. The samples with x a parts per thousand yen 0.25 exhibited insulating behavior in the temperature range from 30 K to 300 K. Addition of LSNO substantially increased the resistivity of the composites. This is attributed to enhanced magnetic disorder at LCMO grain boundaries due to the addition of LSNO. The temperature dependence of the resistivity, rho(T), could be described by the phenomenological percolation model of phase segregation. Fitting the experimental rho(T) data in the temperature range of 30 K to 300 K indicated that the activation energy of the composites increases as a function of the LSNO doping concentration (x).

• 出版日期2014-4