Crystal chemistry of compounds containing mercury in low oxidation states

Abstract

We demonstrated the precise measurement of a 20-V programmable Josephson voltage standard (PJVS) system with an accuracy of 10 À9 . A 20-V PJVS chip including 524288 NbN/TiN x /NbN Josephson junctions (JJs) was used and operated in a cryocooler. By optimizing a microwave frequency, the widest current margin of a voltage step greater than 1 mA was obtained at 15.85 GHz. The maximum voltage of 17 V was also obtained at 18.00 GHz although we could not obtain voltages exceeding 20 V due to defective JJs. We also successfully compared the PJVS system with a 10-V Zener diode with an accuracy of 10 À8 . #

Rigid Covalent Atomic Groups in Precrystallization Phase for Hg-containing Compounds

“…Thus, the formation of mercury-containing crystal structures may be assumed to be the result of primarily the low-resolution (large d hkl ) ordering of the building blocks, the largest in size and mass, by a set of unique crystallographic planes or, in other words, by coordinate planes that form a translation-related sublattice of the building blocks [22,23,25,34]. At the same time, the coordinate planes of unique sublattices can arrange smaller building blocks and single atoms giving high-resolution ordering (smaller d hkl ).…”

“…Mercury atoms can be bonded to oxygen, chalcogen, halogen or some other atoms both in covalent or ionic manner, be bonded to metal atoms to form mono- ([Hg 2 ] 2+ dumbbells, [Hg 3 ] 4+ triangles etc.) and hetero-nuclear clusters with silver, lead and several other metal atoms [22,23]. The crystal chemistry of mercury-containing compounds is of additional interest owing to ecological reasons concerning the occurrence of these compounds in the earth's crust, water and atmosphere.…”

Crystal structural premises to epitaxial contacts for a series of mercury-containing compounds

“…The complexity and multiplicity of crystal chemistry of mercury compounds is manifested in the co-existence of various combinations of ionic and covalent bonds in compounds with various anions (N, O, S, Se, Te, F, Cl, Br or I) [1][2][3]. Many mercury-bearing compounds possess non-centrosymmetric crystal structures and are promising for acentric physical properties [4][5][6][7].…”

The New Mercury Vanadium Phosphate Hg4VO(PO4)2 Containing Hg2+2 Dumbbells: Crystal Structure and Thermal and Magnetic Properties

“…Mercury is known to adopt various oxidation states in inorganic compounds that range from Hg to Hg>, passing through monovalent Hg> dumbbells and polyatomic HgV> L clusters (1). The various dimensionalities and topologies of the latter species (isolated Hg> , linear or planar clusters, etc.)…”