Related papers: Oxygen isotope effect on structural parameters and…
The Fe isotope effect (Fe-IE) on the transition temperature T_c and the crystal structure was studied in the Fe chalcogenide superconductor FeSe_1-x by means of magnetization and neutron powder diffraction (NPD). The substitution of natural…
Isospin effects of the critical phenomena were studied via Xe isotopes in the frame of lattice gas model. All the critical temperatures for four Xe isotopes are close to 5.5 MeV at the same freeze-out density of about 0.39 $\rho_0$. The…
The negative thermal expansion (NTE) mechanism in Cu2O has been characterised via mapping of different Cu2O structural flexibility models onto phonons obtained using ab-initio lattice dynamics. Low frequency acoustic modes that are…
Thermally-densified hafnium terephthalate UiO-66(Hf) is shown to exhibit the strongest isotropic negative thermal expansion (NTE) effect yet reported for a metal-organic framework (MOF). Incorporation of correlated vacancy defects within…
A-site ordered manganites $R$BaMn$_{2}$O$_{6}$ ($R$ = La, Pr, Nd, Sm) were synthesized and the oxygen isotope effect in them was studied. It was found that the substitution of $^{16}$O by $^{18}$O has caused increases in both the Neel…
We report a study of oxygen isotope effects on low temperature specific heat, magnetization, and resistivity of La$_{1-x}$Ca$_{x}$MnO$_{3}$ and (La$_{1-y}$Pr$_{y})_{0.67}$Ca$_{0.33}$MnO$_{3}$. For the metallic compositions of…
Oxygen nonstoichiometry, electrical conductivity and thermal expansion of La2 xSrxNiO4-\delta phases with high levels of strontium substitution (1 =< x =< 1.4) have been investigated in air and oxygen atmosphere in the temperature range…
The isotope effect in the melting temperature of ice Ih has been studied by free energy calculations within the path integral formulation of statistical mechanics. Free energy differences between isotopes are related to the dependence of…
X-ray and neutron powder diffraction data as a function of temperature are analyzed for the colossal dielectric constant material CaCu3Ti4O12. The local structure is studied using atomic pair distribution function analysis. No evidence is…
The results of the Fe isotope effect (Fe-IE) on the transition temperature $T_c$ obtained up to date in various Fe-based high temperature superconductors are summarized and reanalyzed by following the approach developed in [Phys. Rev. B 82,…
We present a detailed room temperature x-ray powder diffraction study on La2-xSrxNiO4+d with 0<=x<=0.12 and 0<=d<=0.13. For x=0.02, 0.04 and 0.06 the oxygen content phase diagrams of the Sr doped samples show a similar sequence of pure…
Magnetic order at room temperature induced by atomic lattice defects, like vacancies, interstitials or pairs of them, has been observed in a large number of different nonmagnetic hosts, such as pure graphite, oxides and silicon-based…
We used temperature-dependent neutron diffraction measurements on FeVO4 to understand the temperature driven anisotropy and observed that the maximum change for a and b lattice parameters in conjunction with a large contraction in angle…
The optical conductivities of films of (La$_{0.5}$Pr$_{0.5}$)$_{0.7}$Ca$_{0.3}$MnO$_3$ with different oxygen isotopes ($^{16}$O and $^{18}$O) have been determined in the spectral range from 0.3 to 4.3 eV using a combination of transmission…
We have studied the oxygen-isotope effect on the superconducting transition temperature $T_{c}$ in overdoped Y$_{1-x}$Ca$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-\delta}$ with $x$ = 0.10, 0.20, and 0.25. We find the oxygen-isotope exponent $\alpha_{O}$…
The work functions of 7Li and 6Li metals have been measured as a function of temperature, by using photoionization of pure isolated metal nanoparticles in a beam. These data reveal a marked isotope effect in the temperature variation of…
Ca2RuO4 is a structurally-driven Mott insulator with a metal-insulator transition at TMI = 357K, followed by a well-separated antiferromagnetic order at TN = 110 K. Slightly substituting Ru with a 3d transition metal ion M effectively…
Linear thermal expansion coefficient (LTEC) of single crystal k-(D4-BEDT-TTF)2Cu[N(CN)2]Br was studied across the crystal layers in the temperature range 2-290 K using the method of precise capacitive dilatometry. Below Tc = 11,6 K the LTEC…
We study the isotope effect on the temperature of the proton order/disorder phase transition between ice XI and ice Ih, using the quasiharmonic approximation combined with \textit{ab initio} density functional theory calculations. We show…
Lattice dynamics and molecular dynamics studies of the oxides UO2 and Li2O in their normal as well as superionic phase are reported. Lattice dynamics calculations have been carried out using a shell model in the quasiharmonic approximation.…