title: Electric quadrupole interaction of 137Ba in barium fluorohalides.
abstract: The X-ray storage phosphor materials BaFC1 and BaFBr differ greatly in their 137Ba nuclear electric quadrupole interaction, despite a common crystal structure. The quadrupole coupling constant in BaFCl is relatively small and increases rapidly with temperature, in an unusual manner: [CQ[ = 1.7 MHz at T = 296 K, CQ-1(delta CQ/delta T)p = 1.7 x 10(-3) K-1. The coupling BaFBr is [CQ[ = 17.0 MHz at 296 K. The difference in quadrupole coupling at room temperature is explained using an electrostatic point-charge model of the crystals.
authors.affiliation: Division of Materials Science & Technology, CSIRO Australia, Clayton.
authors.forename: T J
authors.initials: TJ
authors.lastname: Bastow
authors.forename: S N
authors.initials: SN
authors.lastname: Stuart
mesh_terms: D001464:Barium / Q000737:chemistry*; D017609:Barium Compounds / Q000737:chemistry*; D001965:Bromides / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D003461:Crystallography; D004563:Electrochemistry; D005459:Fluorides / Q000737:chemistry; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013696:Temperature; D014965:X-Rays
chemical_list: D017609:Barium Compounds; D001965:Bromides; D002712:Chlorides; D007554:Isotopes; D001464:Barium; C055150:barium fluoride; D005459:Fluorides