A.c. conduction through MIM sandwich samples of evaporated thin films of V2O5 and V2O5/B2O3

The a.c. electrical properties of evaporated V₂O₅ and co-evaporated V₂O₅/B₂O₃ films have been investigated. The conductivity in both types of film follows the theory of Elliott for single polaron hopping. The behaviour of capacitance, tangent of loss angle and dielectric loss agrees with the model proposed by Goswami and Goswami. The co-evaporated films of V₂O₅/B₂O₃ show better dielectric properties than simple V₂O₅ with increasing content of B₂O₃. Because of their hygroscopic character, the films with B₂O₃ content larger than 40% are observed to be unstable in the atmosphere.     

Synthesis of New Crystalline Pu(V) Compounds from Solutions: VIII. Structure and Properties of Double Pu(V) Malonates MPuO2(OOC)2CH2 · nH2O (M = Na, NH4, Cs)

Preparation conditions and properties of some double Pu(V) malonates MPuO₂L · nH₂O [L = CH₂(COO)₂; M = Na, NH₄, Cs] were determined. These compounds are isostructural to the corresponding double Np(V) malonates obtained previously. The Pu(V) malonates crystallize in the form of needles from solutions with [L²⁻] = 0.05–0.3 M containing 0.5–2 M of salts of outer-sphere cations as salting- out agents. Dry crystals are stable for no less than 3 weeks. The IR spectra of these compounds were recorded. Their thermal behavior was studied. The outer-sphere cations presumably form ionic bonds with plutonyl(V) cations, which are weakened with an increase in the cation radius. __________ Translated from Radiokhimiya, Vol. 47, No. 5, 2005, pp. 431–433. Original Russian Text Copyright ? 2005 by Krot, Bessonov, Grigor'ev, Makarenkov.     

Synthesis of New Crystalline Pu(V) Compounds from Solutions: VII. Synthesis and Study of MPuO2C2O4 · nH2O with M = NH4 and Cs

Double monooxalates MPuO₂C₂O₄ · nH₂O with NH ₄ ⁺ and Cs⁺ ions in the outer sphere were isolated from weakly acidic aqueous solutions of Pu(V). The unit cell parameters of these compounds were determined. The ammonium salt is isostructural to its neptunyl(V) analog; its structure is characterized by the monodentate cation-cation interaction of plutonyl(V) ions. Cesium plutonyl(V) salt isolated from a solution is not isostructural to the neptunyl(V) compound and is easily dehydrated at room temperature to form tetrahydrate, which transforms to dihydrate at 110°C. The latter compound, according to the IR spectra, can have a network system of cation-cation bonds involving PuO ₂ ⁺ . __________ Translated from Radiokhimiya, Vol. 47, No. 5, 2005, pp. 427–430. Original Russian Text Copyright ? 2005 by Bessonov, Krot, Grigor'ev, Makarenkov.