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In this work, the structural and transport properties of (Nd0.7-xLax)Sr0.3MnO3 manganites with x = 0, 0.1 and 0.2 prepared by solid state reaction route are studied. These compounds are found to be crystallized in orthorhombic structural form. The influence of La substitution in place of Nd at A-site shifts the metal to semiconductor/insulator transition temperature (TMI) peak towards room temperature with x = 0, 0.1 and 0.2. A composition prepared with the value of x = 0.2 in (Nd0.7-xLax)0.7Sr0.3MnO3 manganites (i.e. (Nd0.5La0.2)0.7Sr0.3MnO3), TMI was observed at 289 K which is close to room temperature. The maximum percentage of TCR values of compounds are increasing with average radius <r_A> but %TCR are slightly equal in x = 0.1 and 0.2 as compared to the parent compound. The maximum %TCR value is almost independent with A-site average radius <r_A> in x = 0.1 and 0.2. The electrical resistivity data are explored by different theoretical models and it has been concluded that at low temperature (ferromagnetic metallic region) conduction mechanism presumably due to the combined effect of electron-electron, electron-phonon and electron-magnon scattering, while in paramagnetic semiconducting regime, the variation of resistivity with temperature are explained by (1) Mott variable range hopping mechanism, (2) Adiabatic small polaron hopping and (3) Thermally activated hopping. The polaron hopping and thermal activation energies are decreasing with increase of an average A-site ionic radius (<rA>). An appropriate enlightenment for the observed behavior is discussed in detail.
Thermoelectric properties of the chemically-doped intermetallic narrow-band semiconductor FeGa3 are reported. The parent compound shows semiconductor-like behavior with a small band gap (Eg = 0.2 eV), a carrier density of ~ 10(18) cm-3 and, a large n
The effects of Cu-doping on the structural, magnetic, and transport properties of La0.7Sr0.3Mn1-xCuxO3 (0 < x < 0.20) have been studied using neutron diffraction, magnetization and magnetoresistance (MR) measurements. All samples show the rhombohedra
In pursue of a systematic characterization of rare-earth vanadates under compression, in this work we present a multifaceted study of the phase behavior of zircon-type orthovanadate PrVO$_4$ under high pressure conditions, up until 24 GPa. We have fo
The unusual electronic states found in topological materials can enable a new generation of devices and technologies, yet a long-standing challenge has been finding materials without deleterious parallel bulk conduction. This can arise either from de
The effects of pressure generated in a liquid medium, clamp, pressure cell on the in-plane and c-axis resistance, temperature-dependent Hall coefficient and low temperature, magnetoresistance in CaFe2As2 are presented. The T - P phase diagram, includ