CRYSTAL STRUCTURE AND MAGNETIC PROPERTY OF EUROPIUM(II) ORTHOBORATE.

Abstract

The europium(II) orthoborate Eu//3(BO//3)//2 is trigonal, space group R3c, with a equals 9. 069(1), c equals 12. 542(2) A and Z equals 6. The structure has been refined to R equals 0. 082 for 259 observed reflections with isotropic thermal parameters. The borate contains isolated and planar triangle BO//3**3** minus ions, the anions and Eu atoms being hexagonally packed along c. Each Eu atom is surrounded by 8 oxygens with Eu-O distances varying from 2. 36 to 2. 95 A. The interatomic distances between Eu atoms are 3. 509-4. 200 A for 8 nearest Eu neighbors and 4. 831-5. 450 A for 6-second-nearest Eu neighbors.