相关论文: Irreversible Effects in LaGa1-xMnxO3
The effect of crystal lattice disorder on the conductivity and colossal magnetoresistance in La_{1-x}Ca_{x}MnO_{3} (x \approx 0.33) films has been examined. The lattice defects are introduced by irradiating the film with high-energy (\simeq…
We have studied the effect of irreversibility induced by repeated thermal cycles on the electric transport and magnetization of polycrystalline samples of La0.5Ca0.5MnO3 and La0.325Pr0.3Ca0.375MnO3. An increase of the resistivity and a…
We have studied the effect of metastable, irreversibility induced by repeated thermal cycles on the electric transport and magnetization of polycrystalline samples of La1-xCaxMnO3 (0.48\leq x \leq 0.55) close to charge ordering. With time…
In this work, we investigate the irreversible effects of an applied electric field on the magnetotransport properties of LaAlO3/SrTiO3 conducting interfaces, with focus on their multiband character. We study samples of different types,…
The effects of 2.5 MeV electron irradiation were studied in the superconducting phase of single crystals of LaNiGa$_2$, using measurements of electrical transport and radio-frequency magnetic susceptibility. The London penetration depth is…
The phenomenally large enhancement in conductivity observed when Li-doped MgO crystals are oxidized at elevated temperatures was investigated by dc and ac electrical measurements in the temperature interval 250-673 K. The concentration of…
The infrared reflectivity of a $\rm La_{0.67}Ca_{0.33}MnO_3$ single crystal is studied over a broad range of temperatures (78-340 K), magnetic fields (0-16 T), and wavenumbers (20-9000 cm$^{-1}$). The optical conductivity gradually changes…
A recently developed technique for measuring the isothermal magnetocaloric coefficient ($M_T$) is applied to the study of a superconducting NdBa$_2$Cu$_3$O$_7$ single crystal. Results are compared with magnetization ($M$) and specific heat…
The suppression of superconductivity by substitution effects has been measured in high quality single crystals of U(Pt_{1-x} Pd_x)_3 with 0 <= x <= 0.002. While the superconducting transition temperature T_c varies linearly with residual…
The dielectric permittivity and resistivity have been measured simultaneously as a function of magnetic field in Pr1-xCaxMnO3 crystals with different doping. A huge increase of dielectric permittivity was detected near percolation…
We report on DC and pulsed electric field sensitivity of the resistance of mixed valent Mn oxide based La(5/8-y)Pr(y)Ca(3/8)MnO(3) (y = 0.4) single crystals as a function of temperature. The low temperature regime of the resistivity is…
The magnetic and magnetocaloric properties of Ga1-xCMn3+x have been investigated. Reversible magnetocaloric effect (MCE) occurs near the Curie temperature TC. The magnetic entropy change decreases with increasing x, though TC and…
The transition from insulator to conductor can be achieved in some materials but requires modification of both the arrangement of atoms and their electronic configurations. This is often achieved by doping. Here we reveal a mechanism the…
We report the direct evidence of the possibility of charge segregation in manganites. The high contrast of electric-field-induced local charged states is observed during more than 100 hours at room temperature. These induced states display…
The effect of resistive switching in doped manganites being in the ferromagnetic state has been studied using resistive and magneto-optic methods. The visualization of magnetic structure of La0.75Sr0.25MnO3-x single crystals, and its…
The polycrystalline samples of LaGa1-xMnxO3 (0<x<0.3) has been prepared by solid state reaction route. The phase purity of these samples has been confirmed by powder x-ray diffraction experiments carried out on BL-12 at Indus-2 synchrotron…
Optical reflectivity spectra were measured on cleaved surfaces of La1-xSrxMnO3 single crystals (x=0.175, T_C=283 K) over a temperature range 10-295 K. The optical conductivity $sigma(\omega)$ shows, keeping single-component nature,…
A colossal electroresistance effect is observed around room temperature in a transition metal oxide LuFe2O4. The measurements of resistance under various applied voltages as well as the highly nonlinear current-voltage characteristics…
La-doped ASnO3 (A = Ba, Sr) have great potential as advanced transparent oxide semiconductors due to their large optical bandgap and relatively high electron mobility. The bandgap of Ba1-xSrxSnO3 solid solution increases from 3.2 eV…
Static charge in and on the surface of pyroelectric crystals of LiNbO3 and LiTaO3 in a dilute gas has been shown to ionize gas molecules via electron tunneling. The released electrons and positive ions are focused and accelerated according…