Crystals of the Mn Ba(BO)F phase were grown from a high-temperature solution. This new fluoride borate is built of positively charged [Ba(BO)] blocks, the so-called "anti-zeolite" pattern. Using X-ray single-crystal diffraction, the bulk atomic arrangement in the centrosymmetric tetragonal unit cell in I4/ mcm could be elucidated. Crystals of the (MnF) group-containing solid solution Mn Ba(BO)F are dark brown in color in contrast to the differently colored crystals of (LiF) group-containing "anti-zeolite" LiBa(BO)F ( P4 bc). According to the electron spin resonance and optical spectroscopic investigation, the absorption spectrum of LiBa(BO)F crystals results from the absorption of light by both exciton and free charge carriers and can be tuned by varying the initial composition of the high-temperature solution.

Studied LiNaBa(BO)F (P4bc) solid solution belongs to the new class of "antizeolite" borates with [Ba(BO)] cation pattern, which contains channels filled by anionic clusters. Optical-quality crystals were grown from the compositions with different sodium-lithium ratio. The results of Rietveld refinement based on powder data demonstrate linear increase of parameter a and unit cell volume with Na/(Na + Li) ratio in cation site. Parameter c is less sensitive to the changes in stoichiometry, which is consistent with channel topology of LiNaBa(BO)F structure. Distinctive feature of LiNaBa(BO)F crystals is their deep purple color, which is due to both hole-type and electron-type centers. Crystals are characterized by linear dichroism effect.

No abstract

NaSrR(BO 3 ) 2 (R = Ho−Lu, Y, Sc) compounds were obtained for the first time. Their structures exhibit disordered positions of Sr 2+ and Na + atoms while RO 6 polyhedra are connected through the BO 3 groups. Large distances between R atoms and high transparency in the range of 250−900 nm make them promising for phosphor applications. A pathway to obtain single crystals was shown by growing NaSrY(BO 3 ) 2 and NaSrYb-(BO 3 ) 2 by the top seeded solution growth method with Na 2 O-B 2 O 3 -NaF flux.

No abstract

No abstract

No abstract

No abstract