相关论文: Properties of the hole and electron doped perovski…
The crystal structure and numerous normal and superconducting state properties of layered tetragonal (P4/nmm) LaFeAsO, with F-doping of 11 %, are reported. Resistivity measurements give an onset transition temperature Tc = 28.2 K, and low…
We report detailed dc magnetization, linear and non-linear ac susceptibility measurements on the hole doped disordered cobaltite La$_{0.5}$Ba$_{0.5}$CoO$_3$. Our results show that the magnetically ordered state of the system consists of…
We present a valence transition model for electron- and hole-doped cuprates, within which there occurs a discrete jump in ionicity Cu$^{2+} \to$ Cu$^{1+}$ upon doping, at or near optimal doping in the electron-doped compounds and at the…
Solid state synthesis and physical mechanisms of electrical conductivity variation in polycrystalline, strontium doped indium oxide In2O3:(SrO)x were investigated for materials with different doping levels at different temperatures…
We have performed both in-plane resistivity, Hall effect and specific heat measurements on the thermoelectric cobalt oxide Ca$_{3}$Co$_{4}$O$_{9}$. Four distinct transport regimes are found as a function of temperature, corresponding to a…
We present experimental results on thermoelectric power ({\em S}) and electrical resistivity ($\rho $) of pseudobinary alloys Ho(Al$_x$Co$_{1-x}$)$_2$ ($0 \leq x \leq 0.1 $), in the temperature range 4.2 K to 300 K. The work focuses on the…
Bismuth perovskites ABiO$_3$ (A = Sr, Ba) host a variety of peculiar phenomena including bond-disproportionated insulating phases and high-temperature superconductivity upon hole doping. While the mechanisms underlying these phenomena are…
We present evidence for hole injection into LaAlO3/LaVO3/LaAlO3 quantum wells near a polar surface of LaAlO3 (001). As the surface is brought in proximity to the LaVO3 layer, an exponential drop in resistance and a decreasing positive…
A heavy-mass electron state is realized in a doped valence bond solid (Ti1-xVx)2O3. In this system, itinerant holes mediate the mainly ferromagnetic RKKY interaction between the localized magnetic moments and become readily spin-polarized…
We present a study of delta ($\delta$) doping at LaTiO$_3$/SrTiO$_3$ (LTO/STO) interface with iso-structural antiferromagnetic perovskite LaCrO$_3$ (LCO) that dramatically alters the properties of the two dimensional electron gas (2-DEG) at…
Pyrochlore iridates have recently attracted growing interest in condensed matter physics because of their potential for realizing new topological states. In order to achieve such quantum states, it is essential to understand themagnetic…
The temperature dependence of the electronic and atomic structure of the colossal magnetoresistive oxides $La_{1-x}Sr_{x}MnO_{3}$ (x = 0.3, 0.4) has been studied using core and valence level photoemission, x-ray absorption and emission, and…
Doping $La_2CuO_{4}$ with alkaline-earth, $Ae= Sr,Ba$ generates holes in $La_{2-y-x}Ln_yAe_xCuO_{4}$ ($Ln =$ $Nd,Eu$). A small fraction of the holes, $\check{p} \le $ $0.02$, suppresses 3D-AFM. The rest resides as double holes at $O$ atoms…
Neutron scattering experiments were performed on the undoped and hole-doped Ca$_{2+x}$Y$_{2-x}$Cu$_5$O$_{10}$, which consists of ferromagnetic edge-sharing CuO$_2$ chains. It was previously reported that in the undoped…
Two different kinds of metal transition oxides have been studied for their large thermopower values. The first one corresponds to the Tl-based misfit cobaltite which is a hole-doped metal. We demonstrate that the partial Bi-substitution for…
The spin states and electronic structure of layered perovskite La1.5Ca0.5CoO4 are investigated using fullpotential linearized augmented plane-wave method. All the computational results indicate that the Co2+ ion is in a high-spin state and…
Ultrasound velocity measurements of the pseudo-cubic spin-crossover cobaltite LaCoO$_3$ and the lightly Ni-substituted La(Co$_{0.99}$Ni$_{0.01}$)O$_3$ reveal two types of symmetry-resolved elastic anomaly in the insulating paramagnetic…
We critically investigate the purported existence of a multiglass state in the quantum paraelectrics SrTiO${_3}$ and KTaO${_3}$ doped with magnetic 3d transition metals. We observe that the transition metals have limited solubility in these…
Electron irradiation is investigated as a way to dope the topological insulator Bi2Te3. For this, p-type Bi2Te3 single crystals have been irradiated with 2.5 MeV electrons at room temperature and electrical measurements have been performed…
A comparative study of the effect of Fe and Ni doping on the bismuth based perovskite La0.6Bi0.4MnO3.1, a projected spintronics magnetic semiconductor has been carried out. The doped systems show an expressive change in magnetic ordering…