Accession Number : AD0714692

Title :   Spectroscopic Study of Magnetic Phenomena in DyPO4, DyAsO4, and DyVO4.

Descriptive Note : Technical rept.,

Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF PHYSICS

Personal Author(s) : Wright,John C.

Report Date : AUG 1970

Pagination or Media Count : 158

Abstract : The nearest-neighbor interactions in DyPO4, DyAsO4, and DyVO4 produce a five-line structure in the absorption lines. The relative intensities of the five lines have been measured to obtain the relative populations of the five possible nearest-neighbor spin-configurations as a function of temperature. Ordering temperatures have been found for each crystal by locating the sudden change in the relative intensities. The relative intensities of DyPO4 have been fit with a theoretical B.P.W. calculation for an Ising system. The Zeeman behavior of the three crystals has also been examined. A spin-flip phase transition is found to occur in DyPO4. Two phase transitions have been found in DyAsO4 and DyVO4, but the character of these transitions could not be determined. DyPO4 has been identified as an example of the theoretical three-dimensional Ising model. DyAsO4 and DyVO4 are quite different from DyPO4 and appear to be similar to an X-Y model. (Author)

Descriptors :   (*DYSPROSIUM COMPOUNDS, *MAGNETOOPTICS), (*ULTRAVIOLET SPECTRA, DYSPROSIUM COMPOUNDS), VANADATES, PHOSPHATES, ARSENIC COMPOUNDS, ABSORPTION SPECTRA, ELECTRON TRANSITIONS, MOLECULAR ENERGY LEVELS, WAVE FUNCTIONS, ANISOTROPY, (U)ANISOTROPY

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE