J. Steger

Preparation and properties of some transition metal phosphorus trisulfide compounds

Abstract Transition metal phosphorus trisulfide compounds with the general formula MPS3, with M = Mn, Fe, Ni, have been prepared by chemical vapor transport, vapor sublimation, and direct combination of the elements. Chemical transport is accomplished by using 75 Torr of chlorine gas as a transport agent and a temperature gradient of 750° → 690°C or 700° → 640°C. The structure of these three compounds, which belongs to the monoclinic space group C2 m , is related to that of CdCl2 with a distorted cubic close-packing of the sulfur atoms. Metal atoms and phosphorus-phosphorus pairs occupy the trigonally distorted octahedral holes in a ratio of 2:1 and are ordered throughout the structure. Magnetic susceptibility measurements indicate that all three compounds are antiferromagnetic. The paramagnetic moments indicate that the metal ions in each case exist in the divalent high-spin state.

Magnetic susceptibility of MnIn2S4

Abstract Recent magnetic resonance results suggest that MnIn 2 S 4 is antiferromagnetic with a Neel point near liquid helium temperature, in disagreement with previously reported dc (direct current) susceptibility measurements. The resonance data suggest that these susceptibility measurements were made at an applied dc field comparable to or greater than the critical field. This would tend to obscure observation of a magnetic transition, since some of the spins would be “flopped.” The susceptibility measurements have been repeated at a much lower applied field. From these new measurements, a Neel temperature of 4.9°K is obtained, in agreement with the resonance data, and an exchange parameter of 1430 is computed.

Preparation and characterization of the solid solution series Co1−xNixAsS(0 ⩽ x ⩽ 1)

Abstract Both single crystal and polycrystalline samples of the series Co 1− x Ni x AsS0 ⩽ x ⩽ 1 have been prepared. The materials have been characterized by X-ray diffraction, density, and chemical analysis. X-ray intensity data collected for the end member NiAsS shows anion ordering consistent with the ullmanite structure (space group P 2 1 3). Magnetic data indicate that nickel ( d 7 ) is present in the low-spin state. Electrical data show that one additional electron/Ni atom is contributed to the otherwise empty σ* band of CoAsS.

Social class and group therapy in a working class population

In a clinic in which the assignment of patients to therapy was demonstrated as not affected by social class and in which no patient was excluded as unsuitable, 45% of those referred to group therapy stayed 2 or more years. The only category that consistently correlated with not remaining in treatment was that of unemployment. When unemployed persons were included there appeared to be a significant correlation between a stay of 2 or more years and social class. When only employed persons were considered, this significance disappeared