It is shown that the dielectric response of Ba(0.77)Sr(0.23)TiO(3) nanoparticles at temperatures below 200 K has a frequency and temperature dependence in agreement with the Debye theory with a single relaxation time, which exhibits the Arrhenius law. By contrast, at temperatures above 210 K the dielectric response exhibits a broad range of relaxation times characteristic of relaxor-ferroelectr...

We measured the heat capacity on random alloys of Nd1−xCaxB6 (x < 0.4) in the 0.4 to 300 K temperature range. We calculated the lattice contribution to the specific heat, arising from the Debye-type phonons of the boron framework and Einstein-type oscillators of the cation sublattice. Subtracting lattice and Schottky-type contributions from the measured heat capacity, we find that the electroni...

Cormac Toher,1 Jose J. Plata,1 Ohad Levy,1,* Maarten de Jong,2 Mark Asta,2 Marco Buongiorno Nardelli,3 and Stefano Curtarolo4,† 1Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA 2Department of Materials Science and Engineering, University of California, Berkeley, 210 Hearst Memorial Mining Building, Berkeley, California 94720, USA 3D...

Thermal transport in multilayers (MLs) has attracted significant interest and shows promising applications. Unlike their single-component counterparts, MLs exhibit a thermal conductivity that can be effectively engineered by both the number density of the layers and the interfacial thermal resistance between layers, with the latter being highly tunable via the contrast of acoustic properties of...

We study equilibration of strongly coupled ions in an ultracold neutral plasma produced by photoionizing laser-cooled and trapped atoms. By varying the electron temperature, we show that electron screening modifies the equilibrium ion temperature. Even with few electrons in a Debye sphere, the screening is well described by a model using a Yukawa ion-ion potential. We also observe damped oscill...

One hundred years after the original formulation by Petrus J.W. Debije (aka Peter Debye), the Debye Scattering Equation (DSE) is still the most accurate expression to model the diffraction pattern from nanoparticle systems. A major limitation in the original form of the DSE is that it refers to a static domain, so that including thermal disorder usually requires rescaling the equation by a Deby...

We fit finite-temperature path integral Monte Carlo calculations of the exchange-correlation energy of the 3D finite-temperature homogeneous electron gas in the warm-dense regime [rs ≡ (3/4πn)1/3a−1 B < 40 and ≡ T/TF > 0.0625]. In doing so, we construct a Padé approximant which collapses to Debye-Hückel theory in the high-temperature, low-density limit. Likewise, the zero-temperature limit matc...

We have used polarized Cu K-edge extended x-ray absorption fine structure to investigate the local lattice displacements in the charge-ordered La1.48Nd0.4Sr0.12CuO4 system. The temperature-dependent distance broadening, given by the Debye-Waller factors of the Cu-O bonds measuring local lattice fluctuations, shows a clear steplike increase below the charge stripe order temperature. The results ...

We consider a regular chain of quantum particles with nearest neighbor interactions in a canonical state with temperature T. We analyze the conditions under which the state factors into a product of canonical density matrices with respect to groups of n particles each and under which these groups have the same temperature T. In quantum mechanics the minimum group size n(min) depends on the temp...