金属クラスター化合物Nb_6l_<11-x>Br_xおよびY_<2-x>M_xC_2Br_<2-y>l_y (M=Sr, La, Lu, Th) の結晶構造と物性 Syntheses, Structures and Properties of the Cluster Compounds Nb_6I_<11-x>Br_x and Y_<2-x>M_xC_2Br_<2-y>I_y (M=Sr, La, Lu, Th)
Crystal structure, chemical bonding and physical property are discussed for the metal-rich cluster compound Nb<SUB>6</SUB>I<SUB>11-<I>x</I></SUB>Br<I><SUB>x</SUB></I> containing discrete clusters and the layered cluster compound Y<SUB>2-<I>x</I></SUB>M<I><SUB>x</SUB></I>C<SUB>2</SUB>Br<SUB>2-<I>y</I></SUB>I<I><SUB>y</SUB></I>, focusing on the effect of replacement by other atoms having different mass, size and bonding. Nb<SUB>6</SUB>I<SUB>11-<I>x</I></SUB>Br<I><SUB>x</SUB></I> undergoes a spin cross-over phase transition and with increasing Br content the transition temperature shifts from 274 to 170 K. The highest superconducting transition temperature in the yttrium ethenide halides occurs at a intermediate composition rather than at each end-member.
日本結晶学会誌 38(2), 167-173, 1996-04-30
The Crystallographic Society of Japan