Accession Number : AD0262033

Title :   HYPERFINE INTERACTIONS IN THE GROUND STATE AND FIRST EXCITED STATE OF DY161 IN DYSPROSIUM IRON GARNET

Corporate Author : HEBREW UNIV JERUSALEM (ISRAEL)

Personal Author(s) : BAUMINGER,R. ; COHEN,S.G.

Report Date : MAY 1961

Pagination or Media Count : 1

Abstract : The hyperfine Zeeman splittings in the recoilfree absorption spectrum of the 26 kev gamma ray from Dy-161m in Dy-161 situated in dysprosium iron garnet have been observed. At 85 K, the magnetic hyperfine interactions of the ground state and first excited state of Dy-161 are -400 + or - 40 mc and 455 + or - 40 mc, respectively. The electric quadrupole interactions (eqQ/4) at this temperature are 120 + or - 30 and 90 + or - 30 mc, respectively. At 300 degrees K the effective magnetic field (H sub eff) is 4.6 times smaller, and illustrates the proportionality between H sub eff and spontaneous magnetization of the Dy sub-lattice. Assuming Parks value of -0.37 + or - 0.05 nm for the Dy-161 ground state magnetic moment, H sub eff (85 K) equals 3.5 x 10 to the 6th power oe, and 0.42 + or - 0.08 nm for the magnetic moment of the first excited state were obtained. At 300 K a quadrupole interaction of less than 20 mc was obtained. The strongly temperature dependent quadrupole interaction is interpreted as being largely due to the effective electric field gradient produced at the nucleus by the 4f electrons which should be partially aligned below the Curie temperature. (Author)

Descriptors :   *DYSPROSIUM, *HYPERFINE STRUCTURE, ABSORPTION, ELECTRON TRANSITIONS, EXCITATION, GARNET, IRON COMPOUNDS, MAGNETIC FIELDS, MAGNETIC MOMENTS, MEASUREMENT, NUCLEAR ENERGY LEVELS, QUADRUPOLE MOMENT, TEMPERATURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE