Synthesis of two new orthoborates KBaPr(BO₃)₂ and KBaNd(BO₃)₂

Abstract

Two new rare-earth orthoborates KBaPr(BO 3 ) 2 and KBaNd(BO 3 ) 2 were synthesized using a two-step solid-state reaction, both of them are stable in the temperature range 850-1000°C. KBaNd(BO 3 ) 2 and KBaPr(BO 3 ) 2 show incongruent melting at 1019°С and 1005°С, respectively. Prepared compounds crystallize in the trigonal system with space group R3m with cell parameters of а = 5.5052(12)Å, с = 18.402(8)Å, Z = 3 for KBaPr(BO 3 ) 2 and cell parameters of а = 5.4956(5)Å, с = 18.278(3)Å, Z = 3 for KBaNd(BO 3 ) 2 . These new borates continue the previously described line of isostructural three-cation orthoborates KBaY(BO 3 ) 2 and KBaR(BO 3 ) 2 , by R = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. The identity of the intensity and position of the bands in the IR spectra confirm that these compounds are isostructural and have high degree of homogeneity. A red emission centered at 700-740 nm under UV excitation was observed for synthesized KBaPr(BO 3 ) 2 powder.

Magnetism in the KBaRE(BO3)2(RE = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) series: materials with a triangular rare earth lattice

“…The lattice parameters of the title compounds agree well with those previously reported. 13,14,12,15 As expected, the unit cell parameters decrease with decreasing ionic radius of the rare earth, as shown in Figure 5.…”

“…They agree well with parameters previously reported in this structure type and show good evidence for the lanthanide contraction. Elementary magnetic property measurements show no signs of magnetic ordering above 1.8 K. Further low temperature characterization of these triangular rare earth materials, especially in single crystal form, is of significant interest; because many of these materials have been grown as single crystals [12][13][14][15] , such studies are expected to be reasonably performed. …”