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Electronic Conditions of Diatomic (BN) Anions in the Structure of CaNiBN
Author(s) -
Blaschkowski Björn,
Meyer H.Jürgen
Publication year - 2002
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200206)628:6<1249::aid-zaac1249>3.0.co;2-s
Subject(s) - crystallography , crystal structure , tantalum , electronic band structure , structure type , fermi level , chemistry , electronic structure , materials science , condensed matter physics , physics , metallurgy , computational chemistry , electron , quantum mechanics
CaNiBN was synthesized from Ca, Ni and BN in sealed tantalum containers at 1000 °C. The structure was determined by single‐crystal X‐ray diffraction (P4/nmm, Z = 2, a = 353.24(3) pm, c = 763.59(9) pm, R 1 = 0.019, wR 2 = 0.045 for all collected independent reflections). CaPdBN was synthesized after the same method, and a powder pattern was indexed isotypically (P4/nmm, a = 377.38(1) pm, c = 760.95(4) pm). The CaNiBN structure contains (BN) units with B—N bond lengths of 138.1(4) pm. If the (BN) unit in CaMBN (M = Ni, Pd) is replaced by (C 2 ), the structure can be considered as being isotypic with the structure of UCoC 2 . Crystals of CaNiBN exhibit metallic lustre. According to the calculated band structure an extremely narrow band gap is present. The covalency between Ni and BN is marked by two important σ type interactions. A third type of interaction between (BN) π* and Ni orbitals represents the slightly occupied conduction bands. CaNiBN exhibits temperature independent paramagnetism and no superconducting transition down to 4 K.