STACK Crystal Chemistry

Crystal structures and magnetic properties of iron borates containing lanthanides Sr6LnFe(BO3)6 (Ln = La, Pr, Nd, Sm Lu)

“…The Sr 6 LnFe(BO 3 ) 6 contain two kinds of magnetic ions, Ln 3þ and Fe 3þ , and this combination is expected to have the strongest magnetic interaction among the obtainable A 6 MM 0 (BO 3 ) 6 compounds due to that there exist the Fe 3þ ion having the largest possible spin and the d-f magnetic interaction between Fe 3þ and Ln 3þ ions. The compounds for M ¼ M' ¼ transition metals having the stronger d-d magnetic interaction cannot be obtained because of their smaller ionic radii; the Sc 3þ (0.745 Å) ion is a lower limit to maintain this crystal structure as reported by Schaffers et al [8].…”

“…All the XRD profiles were indexed on a hexagonal unit cell with a ¼ 12.185e12.338 Å and c ¼ 9.154e9.241 Å. These XRD profiles were analyzed by the Rietveld method, and as the starting model of analysis, we used the structural data of Sr 6 YFe(BO 3 ) 6 reported by Schaffers et al [8]. In this model, the Sr 6 YFe(BO 3 ) 6 crystallizes in the hexagonal structure with space group R3, and Sr and Ln ions occupy different crystallographic sites, 18f and 3a, respectively.…”

“…They have a hexagonal unit cell (space group R3), and over 150 compounds have been reported [8] in which A is Sr, Ba, Pd and lanthanides and M, M 0 are þ2, þ3, or þ4 metal cations. The M and M 0 ions are octahedrally coordinated by oxygen ions, and the MO 6 and M'O 6 octahedra are connected by BO 3 triangles.…”

“…In them, only two compounds (Ln ¼ Gd, Ho) have been synthesized up to now [8]. The Sr 6 LnFe(BO 3 ) 6 contain two kinds of magnetic ions, Ln 3þ and Fe 3þ , and this combination is expected to have the strongest magnetic interaction among the obtainable A 6 MM 0 (BO 3 ) 6 compounds due to that there exist the Fe 3þ ion having the largest possible spin and the d-f magnetic interaction between Fe 3þ and Ln 3þ ions.…”

Optical features of calcium neodymium oxyborate Ca4NdO(BO3)3 doped by Yb3+

“…Another family of oxyborates, with * Corresponding author. the composition A 6 MM (BO 3 ) 6 where A = Sr or Ba, have been found [8,9]. The metal ion M and M comprise several metal ions, whose sum of formal charges add up to +6.…”