Improvement of high- and low-temperature characteristics of nickel–metal hydride secondary batteries using rare-earth compounds is discussed. High-temperature charge characteristics are improved by coating a sintered positive electrode with yttrium hydroxide due to the increased oxygen evolutio...

The topochemistry of hydride formation in the rare earth metals was investigated by metallographic examination of partially hydrogenated samples. The effects of surface overlayers (“oxides”) on the development of the hydride phases are discussed and are related to measured overall reaction rat...

The influence of hydrogen on the magnetic structures in thulium was determined by measuring the temperature dependence of the electrical resistivity up to 75 K. The H acts by lowering the Neel temperature and the spin-disorder resistivity, by smearing out the manifestation of the Curie temperatu...

Solid solutions of hydrogen in thulium are investigated, mainly by X-ray determinations in the temperature range 20–500°C. Several observations lead us to distinguish between two variaties α and α∗. In the range of existence of the α∗ phase, below the transition temperature of 120°C, the h...

High precision electrical resistance measurements were performed in the temperature range from 4.2 K up to room temperature on a pure thulium bulk sample with a high residual resistivity ratio, RRR=146, and on thulium thin films in the thickness interval from 25 to 115 nm. The observed size-effe...

Temperature dependences of heat capacity CP(T) and lattice parameters a(T), b(T), c(T) of thulium carboboride TmB2C at 2–300 K were experimentally studied. Magnetic phase transition in the carboboride – ‘paramagnetic – antiferromagnetic’ at TN = 11.0 K was revealed. By comparison with the d...

Intermetallic compounds Tb7Rh3 and Dy7Rh3, which crystallize in Th7Fe3 type hexagonal structure with the space group P63mc were hydrogenated under high hydrogen pressure in order to study influence of hydrogen on their structural and magnetic properties.Hydrogen treatment of Tb7Rh3 and Dy7Rh3 ev...

The magnetocaloric effect (MCE) in the magnetic terbium dihydride TbH1.92, TbH2.03 and TbH2.09 samples has been evaluated from the heat capacity Cp(T) measurements under-zero field and 9 T. The MCE phenomena in the vicinity of the magnetic phase transitions in terms of the magnetic-entropy chang...

The electronic structure and equilibrium properties for the cubic rare earth superstoichiometric dihydride TbH2.25 are calculated using the full-potential linearized augmented plane wave method (FP-LAPW) within the density functional theory (DFT) in the generalized gradient approximation (GGA) a...

Specific heat measurements were made in the temperature range of 2–300 K on TbH3 and ErH2.98 trihydride samples. The magnetic Schottky anomaly was separated from the experimental Cp(T) data by subtracting the lattice heat contribution of the non-magnetic LuH3 hydride. The Schottky contribution ...

The effect of mechanical activation (MA) on the kinetics of terbium (Tb) leaching from waste phosphors using hydrochloric acid was investigated. Leaching kinetics, such as apparent reaction rate, activation energy and reaction order, were determined using the shrinking-core model and the Arrheni...

Pressure induced phase transformation in terbium trihydride has been studied by X-ray diffraction and Raman spectroscopy up to 20 GPa. Theoretical calculations were performed using density functional theory (DFT) with the Perdew–Burke–Ernzerhof parameterizations of the generalized gradient app...

The refining of terbium (Tb) by plasma arc melting using pure Ar and Ar + H2 mixture was examined, respectively. The temperature distribution and gas flow of the plasma arc during the melting process were simulated. The residual metallic impurities were examined by inductively coupled plasma-ato...

Magnetization measurements of terbium dihydride samples with different hydrogen concentration, TbH1.92, TbH1.99, TbH2.03 and TbH2.09, in the temperature range from 1.8 to 300 K and at an applied field of 1 kOe are reported. Two first-order antiferromagnetic transitions have been registered in th...

Work function changes ΔΦ caused by H2 interaction with thin terbium and europium films deposited on glass under UHV conditions were correlated with hydrogen uptake and electrical resistance R, measured in situ. For both metals, the course of ΔΦ(H/Me) at room temperature confirms the change i...

We show here that a palladium capped samarium film at room temperature can be used as an efficient sensor material for hydrogen detection. As low as 194 ppm of hydrogen gas can be detected without any cross sensitivity problem. Depending upon the partial pressure of hydrogen, response times vary...

The unit cell parameters of the trihydride GdH3 (Pearson symbol hP24, space group P3̄c1, HoH3 type) were determined employing Guinier powder diffraction patterns. The structure of the interstitial compound GdH3 is formed by departing from a hexagonal close-packed substructure of gadolinium and b...

High-pressure studies of samarium trihydride have been performed in a diamond anvil cell at pressures up to 30 GPa at room temperature. As a result, a reversible structural phase transformation from the hexagonal to the cubic phase has been observed. The transition pressure and the lattice param...

1.1. Numerous esters of phosphoric, thiophosphoric and phosphinic acids have been synthesized and are described.2.2. The activity of esters as additives for reducing wear under high loads depends on ester structure. Esters containing thiol sulphur are more active than esters containing thionic s...

In order to study the relationship between the thermal stability and antiwear performance of metal-free phosphorus-sulphur compounds, some mono- and dithiophosphoric acid -O,O,S- triesters with specifically modified structures were synthesized and characterized by elemental analysis and 31P NMR ...