Related papers: Melting of the Na layers in solid Na0.8CoO2
A new extended solid nitrogen, referred to post-layered-polymeric nitrogen (PLP-N), was observed by further heating the layered-polymeric nitrogen (LP-N) to above 2300 K at 161 GPa. The new phase is found to be very transparent and exhibits…
Comprehensive studies of the low-temperature specific heat C(T,H) in NaxCoO2-yH2O are presented. At H=0, a very sharp anomaly was observed at T=4.7 K indicating the existence of bulk superconductivity. There exists the T^2 term in C(T,H=0)…
The determination by powder neutron diffraction of the ambient temperature crystal structures of compounds in the NaxCoO2 family, for 0.3 < x <= 1.0, is reported. The structures consist of triangular CoO2 layers with Na ions distributed in…
Melting of rhombohedral boron subnitride B13N2 has been studied in situ at pressures to 8 GPa using synchrotron X-ray diffraction and electrical resistivity measurements. It has been found that above 2.6 GPa B13N2 melts incongruently, and…
Neutron diffraction studies as a function of temperature on solid solutions of MnSe and MnTe in the Se rich region are presented. Interestingly as Te is doped in MnSe, the structural transformation to NiAs phase diminishes, both in terms of…
Na-ion conduction, and correlations between Na-ion conduction pathways and crystal structure have been investigated as a function of temperature in the layered battery material Na2Ni2TeO6 by impedance spectroscopy and neutron diffraction,…
We report muon-spin rotation, heat capacity, magnetization, and ac magnetic susceptibility measurements of the layered spin-1/2 antiferromagnet NaNiO2. These show the onset of long-range magnetic order below T_N = 19.5K. Rapid muon…
We report the results of low-temperature measurements of the specific heat Cp(T), ac susceptibility chi(T) and 23Na nuclear magnetic resonance NMR of Na2V3O7. At liquid He temperatures Cp(T)/T exhibits broad field-dependent maxima, which…
The solid-state reaction was used to synthesize CoO2 nanostructured material. Cobalt nitrate tetrahydrate and sodium oxide (NaOH) were combined to produce CoO2 nanostructured material. The three synthesized working electrodes were each…
Molecular dynamics simulation have shown that after initial surface melting, nanowires can melt via two mechanisms: an interface front moves towards the wire centre; the growth of an instability at the interface can cause the solid to…
We characterise the structural properties of the quasi-liquid layer (QLL) at two low-index ice surfaces in the presence of sodium chloride (Na$^+/$Cl$^-$) ions by molecular dynamics simulations. We find that the presence of a high surface…
The CoO$_{2}$ layers in sodium-cobaltates Na$_{x}$CoO$_{2}$ may be viewed as a spin $S=1/2$ triangular-lattice doped with charge carriers. The underlying physics of the cobaltates is very similar to that of the high $T_{c}$ cuprates. We…
A series of layered nickel-based LaO$_{1-x}$F$_x$NiAs compounds with x=0 to 0.15 are synthesized by solid state reactions. The pure LaONiAs exhibits bulk superconductivity with Tc $\sim$ 2.75 K. Partial substitution of oxygen by fluorine…
Soda-lime-silica is a glassy system of strong industrial interest. In order to characterize its liquid state properties, we performed molecular dynamics simulations employing an aspherical ion model that includes atomic polarization and…
We report measurement of room-temperature compressibility, thermal expansion, thermoelectric power a(T) at various pressures P < 20 kbar, basal-plane resistivity rab (T), magnetic susceptibility and thermal conductivity k(T) taken on…
We report the temperature and time dependence of electrical resistivity on high temperature, high oxygen pressure prepared polycrystalline samples of NdNiO_3. NdNiO_3 is metallic above 195 K and below that temperature it undergoes a…
We report on {23}Na NMR studies of a honeycomb lattice antiferromagnet Na2Ni2TeO6 by {23}Na nuclear spin-echo techniques. The {23}Na nuclear spin-lattice relaxation rate 1/{23}T_1 exhibits critical divergence near a Neel temperature T_N =…
Thermochemical characteristics of Nd1+xBa2-xCu3Oy solid solutions were studied by solution calorimetry. Dependences of formation enthalpies from Nd content were constructed. It was established that decomposition of solid solution on the…
A series of CaxCoO2 (0.15 <= x <= 0.40) materials have been prepared by means of ion exchange reaction from NaxCoO2. Transmission electron microscopy (TEM) measurements revealed a rich variety of structural phenomena resulting from cation…
New electronic phases have been identified and placed in the (T,H) phase diagram of metallic NaxCoO2. At low Na-content (x = 0.36), the magnetic susceptibility diverges with a power law T^(-n), n<1, and shows (T,H) scaling, indicating the…