相关论文: Localized polarons and conductive charge carriers:…
The fate of electric dipoles inside a Fermi sea is an old issue, yet poorly-explored. Sr$_{1-x}$Ca$_x$TiO$_{3}$ hosts a robust but dilute ferroelectricity in a narrow ($0.002<x<0.02$) window of substitution. This insulator becomes metallic…
This review will deal with several types of free charge localisation in oxides and their consequences on the effective dielectric spectra of such materials. The first one is the polaronic localisation at the unit cell scale on residual…
We investigated the dielectric response of CaCu$_3$Ti$_4$O$_{12}$ (CCTO) thin films grown epitaxially on LaAlO$_3$ (001) substrates by Pulsed Laser Deposition (PLD). The dielectric response of the films was found to be strongly dominated by…
Recently a growing number of experiments have provided indications of the key role of polarons (composite particles formed by a charge strongly coupled with a local lattice deformation) in doped perovskites, hosting colossal…
CaCu3Ti4O12 (CCTO) ceramics which has perovskite structure gained considerable attention due to its giant permittivity. But, it has high tan {\delta} (0.1 at 1kHz) at room temperature, which needs to be minimised to the level of practical…
We report the temperature dependence of transport and magnetic properties of La$_{1-x}$Ca$_x$VO$_3$ for x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5. The system exhibits an insulator-to-metal transition concomitant with an…
Two extreme members of the cobaltite series, LaCoO3 and DyCoO3, were investigated by the electrical resistivity and thermopower measurements up to 800-1000 K. Special attention was given to effects of extra holes or electrons, introduced by…
Dc and ac transport properties as well as electric modulus spectra have been investigated for the samples LaMn$_{1-x}$Fe$_{x}$O$_3$ with compositions 0 $\leq x \leq$ 1.0. The bulk dc resistivity shows a temperature variation consistent with…
The 2D lattice gas model with competing short and long range interactions is appliedused for calculation of the incoherent charge transport in the classical strongly-correlated charge segregated polaronic state. We show, by means of…
The question whether excess electrons in SrTiO3 form free or trapped carriers is a crucial aspect for the electronic properties of this important material. This fundamental ambiguity prevents a consistent interpretation of the puzzling…
Measurements of the low-frequency (f<= 100 kHz) permittivity at T<= 160 K and dc resistivity (T<= 430 K) are reported for La(1-x)Ca(x)MnO(3) (0<= x<= 0.15). Static dielectric constants are determined from the low-T limiting behavior of the…
We show results of broadband dielectric measurements on the charge ordered, proposed to be mul- tiferroic material LuFe2O4. The temperature and frequency dependence of the complex permittivity as investigated for temperatures above and…
Lithium titanium oxide Li$_4$Ti$_5$O$_{12}$ (LTO) is an intriguing anode material promising particularly long lived batteries, due to its remarkable phase stability during (dis)charging of the cell. However, its usage is limited by its low…
Some possible connection between spin and charge degrees of freedom in magneto-resistive manganites is investigated through a thorough experimental study of the magnetic (AC susceptibility and DC magnetization) and transport (resistivity…
In the colossal magnetoresistance manganites polarons have been proposed as the charge carrier state which localizes across the metal-insulator transition. The character of the polarons is still under debate. We present an assessment of…
We report a rather high dependence of the dielectric permittivity on the magnetic field in La2/3Ca1/3MnO3. The variation is maximum at around 270 K, little above the Curie temperature, TC, and it reaches a 30% under only 0.5 T. We attribute…
We present a hybrid quantum-classical simulation of charge-polaron transport in conjugated polymers. The charge, which couples to the angular rotations of the monomers, is modeled via the time-dependent Schr\"odinger equation, while the…
We have investigated the complex dielectric and impedance properties of magnetoelectric compound Fe2TiO5 (FTO) as a function of temperature (T) and frequency (f) to understand the grain (G) and grain boundary (Gb) contributions to its…
We present heat capacity, electrical and thermal transport measurements of kagome metals $A$V$_3$Sb$_5$ ($A$ = K, Rb, Cs). In all three compounds, development of short-range charge fluctuations above the charge density wave (CDW) transition…
The Poly(vinylidene fluoride)/CaCu3Ti4O12 (CCTO) nanocrystal composite films (85nm) with relatively high dielectric permittivity (90 at 100Hz) were prepared by the solution casting followed by spin coating technique. The structural, the…