H.-C. zur Loye

Synthesis, structure, and magnetic properties of the layered bismuth transition metal oxide solid solution Bi2Fe4−xGaxO9

The solid solution Bi{sub 2}Fe{sub 4{minus}x}Ga{sub x}O{sub 9} (0 {le} x {le} 4) was synthesized and investigated by X-ray diffraction, Moessbauer spectroscopy, and susceptibility measurements. The system was found essentially to follow Vegards law. The crystal structure of the x = 2 member, Bi{sub 2}Fe{sub 2}Ga{sub 2}O{sub 9}, was solved. The structure is orthorhombic with space group Pbam (No. 55), a = 7.946(1) {angstrom}, b = 8.355(1){angstrom}, and c = 5.929(1) {angstrom}. Iron and gallium were nonstatistically distributed over two octahedral and two tetrahedral sites. The iron displayed a 60% preference for the octahedral positions. Magnetic susceptibility and Moessbauer measurements showed antiferromagnetic behavior. The ordering temperature, T{sub N}, exhibited a strong dependence on x, decreasing rapidly with gallium doping from T{sub N} = 245 {plus minus} 5 K for x = 0 to T{sub N} {lt} 4.2 K for x = 3. Spin-glass-like behavior was observed in the gallium-substituted compounds, and a previously undetected spin rearrangement at 220 K for the x = 0 compound is reported.

Crystal growth of two new photoluminescent oxides: Sr3Li6Nb2O11 and Sr3Li6Ta2O11.

Single crystals of Sr3Li6M2O11 (M = Nb, Ta) were grown out of a high-temperature Sr(OH)2/LiOH/KOH flux. The single crystal X-ray diffraction data were indexed to the orthorhombic Pmma system, with a = 10.5834(15) A, b = 8.3103(13) A, c = 5.8277(8) A, V = 512.55(13) A(3), and Z = 2 for Sr3Li6Nb2O11 and a = 10.5936(6) A, b = 8.3452(5) A, c = 5.8271(4) A, V = 515.15(6) A(3), and Z = 2 for Sr3Li6Ta2O11. The crystal structure consists of sheets of interconnected SrO8 polyhedra that are separated by M-O layers and an intervening LiO(x) polyhedral framework, representing a new structural type. The M-O layers exhibit a rare occurrence of both five- and six-coordinated M(5+) ions in the same structure. The oxides, upon excitation at 250 nm, exhibit violet emission at room temperature.

Structure of Indium Iron Oxide

InFe 3 is isostructural with the recently reported InMnO 3 . The structure of InFeO 3 contains layers of In-O octahedra and Fe-O trigonal bipyramids. The trigonal bipyramids have ideal D 3h symmetry. This unusual structure is unexpected within the context of known sesquioxide structures

Synthesis and structure of Bi2Fe2Mn2O10

Abstract The crystal structure of a new material, Bi 2 Fe 2 Mn 2 O 10 , in the Bi-Fe-Mn-O system has been determined to be isostructural with Bi 2 Mn 4 O 10 . Single-crystal studies show the space group to be Pbam (No. 55) with unit-cell parameters a =7.617(3) A, b =8.548(4) A and c =5.830(3) A.This new compound has ordered iron and manganese ions in octahedral and square pyramidal sites respectively. This is the first reported example of a quaternary phase with the general structure type of Bi 2 M 4 O 9+8 (M  Al, Fe, Ga, Mn) having ordered transition metal cations.

Laser deposition of oriented BiMeVOx films

Abstract The oxygen-ion conducting ceramics Bi 2 VO 5.5 and Bi 2 Cu 0.1 V 0.9 O 5.35 were synthesized and deposited on several substrates by the pulsed laser deposition technique. Defect-free films of Bi 2 Cu 0.1 V 0.9 O 5.35 were obtained on SrTiO 3 substrates, while films of Bi 2 VO 5.5 exhibited severe cracking. Reasons for the different results are discussed.

Recent developments in ternary nitride chemistry

Recent developments in the synthesis, structures, and properties of ionic/covalent ternary nitrides are reviewed. A description, including synthetic conditions, is given of preparative methods reported in the literature. Solid state synthetic reactions from binary nitrides as well as novel synthetic approaches such as amide synthesis and ammonolysis of ternary oxides are described. Examples of common structure types as well as electronic and magnetic properties are discussed.