Multianvil High-Pressure Synthesis of Dy₄B₆O₁₅:  The First Oxoborate with Edge-Sharing BO₄ Tetrahedra

Abstract

In all known oxoborates the linkage of BO(3) and BO(4) groups is performed via common corners. Here we present the high-pressure/high-temperature synthesis of Dy(4)B(6)O(15), which is the first oxoborate exhibiting edge-sharing BO(4) tetrahedra.

High-pressure Synthesis and Characterization of the Alkali Metal Borate HP-RbB3O5

“…In contrast, high-pressure borates often exhibit an increasing amount of tetrahedrally coordinated boron atoms. Even the structural motif of two edge-sharing BO 4 tetrahedra forming a B 2 O 6 group is possible under high-pressure conditions, as first discovered in Dy 4 B 6 O 15 [11]. Meanwhile several other high-pressure phases are known to contain this B 2 O 6 group, e. g. RE 4 B 6 O 15 , (RE = Dy, Ho) [11,12], α-RE 2 B 4 O 9 (RE = Sm, Eu, Gd, Tb, Ho) [13,14] [19].…”

Synthesis of Er5(BO3)2F9 and Properties of RE5(BO3)2F9 (RE = Er, Yb)

“…The arrangement can be described via alternating layers of the formal compositions "ErBO 3 " and "ErF 3 ", spreading into the bc-plane. For a more detailed description of the structure, including a comparison to the related structures of RE 3 (BO 3 ) 2 F 3 (RE = Sm, Eu, Gd) [5] and Gd 2 (BO 3 )F 3 [6], the reader is referred to the description of the isotypic compound Yb 5 (BO 3 ) 2 F 9 (ref. [1]).…”

“…E.g., during our studies of high-pressure phases of the rareearth borates, the compounds RE 4 B 6 O 15 (RE = Dy, Ho) [6][7][8] were intensively investigated. Nevertheless, it was not possible to obtain isotypical compounds with RE = Er, Tm, Yb, or Lu.…”

Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4

“…Besides HP-NiB 2 O 4 and β -FeB 2 O 4 , there are two other borate structure types with the motif of B 2 O 6 units: the rare-earth borates α-RE 2 B 4 O 9 (RE = SmHo) [8 -11] and RE 4 B 6 O 15 (RE = Dy, Ho) [8,12,13]. pressure borates exhibiting edge-sharing BO 4 [52].…”

“…Two new rare-earth borates, α-RE 2 B 4 O 9 (RE = Sm-Ho) [8 -11] and RE 4 B 6 O 15 (RE = Dy, Ho) [8,12,13], exhibit edge-sharing BO 4 tetrahedra, a new structural motif in the chemistry of oxoborates. This motif could also be found in HP-NiB 2 O 4 [14], which is the first borate to show exclusively BO 4 tetrahedra sharing one common edge with a second one.…”