Rb Compounds Research Articles

New ferroelectrics of the (NH4)2SO4type

Abstract The compositions Rb2ZnCl4, Rb2ZnBr4, Rb2CoCl4, Rb2CoBr4 and {N(CH3)4}2CoCl4 have been found to be ferroelectric. The Curie temperatures of these Rb compounds are near −80°C. (N(CH3)4}2CoCl4 is ferroelectric in a narrow temperature range of 4.6–7.1°C.

Structural evidence for xenon-chlorine bonding: neutron and x-ray diffraction determinations of the structure of cesium and rubidium trioxodichloroxenate(VI) chloride, Cs9(XeO3Cl2)4Cl and Rb9(XeO3Cl2)4Cl

The compounds XeO/sub 3/ . 2.25 CsCl and XeO/sub 3/ . 2.25 RbCl have been structurally characterized as cesium and rubidium trioxodichloroxenate(VI) chloride, M/sub 9/(XeO/sub 3/Cl/sub 2/)/sub 4/Cl, using single-crystal counter diffraction methods. The crystals are body-centered tetragonal, point group 4/m, with a = 16.56 A and c = 7.10 A for the Cs salt and a = 15.97 A and c = 6.91 A for the Rb salt, and contain eight XeO/sub 3/ . 2.25 MCl formula units per unit cell. The structures have been refined in the space group I anti 4 to R factors of 8.3% for the Cs compound using neutron data and 10.4% for the Rb compound using x-ray data. The crystal structures contain infinite chains, parallel to c, of XeO/sub 3/Cl/sup -/ units linked by nearly linear chlorine bridges. The metal cations and one-ninth of the chlorine atoms are separated from the repeating polymeric unit XeO/sub 3/Cl/sub 2//sup 2 -/ by nonbonding distances. The xenon coordination is octahedral (distorted) with three terminal oxygen neighbors (in the Cs salt) at 1.77 A, one terminal Cl neighbor at 2.96 A, and two bridging Cl neighbors at 2.95 and 2.97 A.

Magnetic interactions in 3-dimensional B.C.C. Heisenberg ferromagnets. III. (K,NH 4) 2CuCl 4·2H 2O

Nuclear-resonance techniques are used to determine the magnetic and electric quadrupole interactions of the nuclei of all ions (except O 2−) in the two compounds. The magnetic behaviour of these compounds, including the direction of the spontaneous magnetization and the occurence of spontaneous magnetostriction effects in zero field below T c, is quite analogous to that observed for the isomorphous Rb and Cs compounds. In the paramagnetic state in an external field a finestructure on some of the chlorine resonance lines has been observed. Experimental results on the field and temperature dependence of these line splittings are given.

Proton magnetic resonance study of RbH3(SeO3)2 and CsH3(SeO3)2

A Proton Magnetic Resonance study using both CW and pulse techniques has been made of rubidium trihydrogen selenite and cesium trihydrogen selenite. The hydrogens are found to be in two nonequivalent sites in these compounds. Some of the energies required for stretching and breaking of the hydrogen bonds have been determined. There is some evidence that a phase transition below -160°C for the Rb compound is triggered by the hydrogens, while a reported antiferroelectric transition for the Cs compound is not confirmed by hydrogen dynamics.

Magnetic interactions in 3-dimensional B.C.C. Heisenberg ferromagnets. I. (NH4, Rb)2CuBr4·2H2O

Abstract Nuclear-resonance techniques are used to determine the magnetic and electric quadrupole interactions of the nuclei of all ions (except O2−) in the two compounds. The magnetic behaviour of these compounds, including the direction of the spontaneous magnetization and the occurence of spontaneous magnetostriction effects in zero field below Tc, is quite analogous to that observed for the isomorphous Rb and Cs compounds. In the paramagnetic state in an external field a finestructure on some of the chlorine resonance lines has been observed. Experimental results on the field and temperature dependence of these line splittings are given.

Some observations of Pu(IV)-alkali double chlorides

Mixtures of PuCl/sub 3/ and the alkali chlorides, in the mole ratio 1; 2, were melted and saturated with chlorine at 0.80 atm pressure and approximately 50 deg C above the melting point. No reaction of chlorine with the solution PuCl/ sub 3/ + 2LiCl was detected. Products of reaction of chlorine with solutions of PuCl/sub 3/ + 2NaCl and PuCl/sub 3/ + 2RbCl are optically isomorphous with Cs/sub 2/PuCl/sub 6/. Products of reaction of chlorine with the solution PuCl/sub 3/ + 2KCl are too fine grained to establish the isomorphism with certainty. The common reaction must be PuCl/sub 3/(l) + 2MCl(l) + 1/2Cl/sub 2/(g) = M/sub 2/uCl/ sub 6/ ( l); where M = Na, K, Rb, or Cs. Ranges of the non-stationary arrests indicate that the compounds containtng Na and K, and probably the Rb compound, are partly dissociated under the given conditions and that the stabilities of the M/sub 2/PuCl/sub 6/ compounds increase in the order Na, K, Rb, and Cs. Results are believed to confirm the opinion that appreciable quantities of Pu(IV) may be formed in binary solutions of most alkali chlorides with PuCl/sub 3/ when exposed to chlorine gas. (P.C.H.)