Showing papers by "Pham Thanh Phong published in 2010"
TL;DR: In this article, the effect of particle size on magnetic and electrical properties was investigated and a phenomenological model, describing competition between the FM and PI phases was used to elucidate temperature dependence of the resistivity with and without magnetic field, agrees quantitatively with experimental observations.
30 citations
TL;DR: In this paper, the electrical transport properties and magnetoresistance of La 0.7 Ca 0.3 MnO 3 /La 0.1 MnO3 composites are investigated as a function of sintering temperature.
26 citations
TL;DR: In this paper, the effect of grain size on low-field magnetoresistance (LFMR) has been investigated based upon a phenomenological model taking into account the spin-polarized transport across grain boundaries.
23 citations
TL;DR: In this paper, the effect of particle size on magnetic and electrical properties was investigated and a phenomenological model, describing competition between the FM and PI phases was used to elucidate temperature dependence of the resistivity with and without magnetic field, agrees quantitatively with experimental observations.
Abstract: Nanocrystalline samples of La0.7Ca0.3MnO3 were synthesized by reactive milling method and annealed at various temperatures. Effect of particle size on the magnetic and electrical properties was investigated. While the ferromagnetic–paramagnetic transition temperature TC does not show significant change, metal–insulator TMI is markedly affected by particle size. Experimental data indicates linear relationship of magnetization and resistivity to the surface/volume ratio of the particles with different mean sizes. A phenomenological model, describing competition between the FM and PI phases used to elucidate temperature dependence of the resistivity with and without magnetic field, agrees quantitatively with experimental observations.
1 citations