Accession Number : ADP008276
Title : Persistent Spectral Hole-Burning Induced by Ion-Tunneling in Hydrogenated CaF2:Pr3+ and SrF2:Pr3+ Crystals,
Corporate Author : IBM RESEARCH DIV SAN JOSE CA
Personal Author(s) : Reeves, R. J. ; Macfarlane, R. M.
Report Date : 22 MAY 1992
Pagination or Media Count : 4
Abstract : The crystal systems of CaF2:Pr3+ and SrF2:Pr3+ into which H-, D-, or Tions have been diffused exhibit persistent spectral hole-burning when particular Pr3+ ion centers are resonantly excited. 1 The H- ions replace lattice and interstitial F- ions. The hole-burning is caused by H- (or D-, T-) ion motion in the lattice following the Pr3+ excitation and the holes have lifetimes of at least several hours at low temperatures. The group of centers that undergo this process have rhombic symmetry and are modified from the predominant C4v H- hydrogenic center by the addition of extra hydrogenic ions in the near neighbor coordination cube. A number of centers are produced because there are several different positions where these extra ions can be located. The degenerate E ground state of the C4v parent center is split by the rhombic field resulting in singlet ground states for the Pr3+ ion. Of particular interest is the fact that the centers differ greatly from one another in the strength of the rhombic distortion and hence the splitting, A, of the ground state E level. This has dramatic consequences for the magnetic properties of the ground states and for the pseudoquadrupole splittings of l4lPr.
Descriptors : *CRYSTALS, *IONS, *TUNNELING, *HYDROGENATION, *CALCIUM FLUORIDES, *PRASEODYMIUM, ADDITION, DISTORTION, EXCITATION, GROUND STATE, INTERSTITIAL, MAGNETIC PROPERTIES, MOTION, NUMBERS, SPLITTING, SYMMETRY, TEMPERATURE, CHEMICAL REACTIONS, STRONTIUM COMPOUNDS, FLUORIDES, DIFFUSION, RESONANCE, CRYSTAL LATTICES, MOLECULAR SPECTROSCOPY, QUADRUPOLE MOMENT, RHOMBUS.
Subject Categories : Solid State Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE