title: Hydrothermal Synthesis and Characterization of Novel Brackebuschite-Type Transition Metal Vanadates: Ba2M(VO4)2(OH), M = V(3+), Mn(3+), and Fe(3+), with Interesting Jahn-Teller and Spin-Liquid Behavior.
abstract: A new series of transition metal vanadates, namely, Ba2M(VO4)2(OH) (M = V(3+), Mn(3+), and Fe(3+)), was synthesized as large single crystals hydrothermally in 5 M NaOH solution at 580 °C and 1 kbar. This new series of compounds is structurally reminiscent of the brackebuschite mineral type. The structure of Ba2V(VO4)2(OH) is monoclinic in space group P21/m, a = 7.8783(2) Å, b = 6.1369(1) Å, c = 9.1836(2) Å, β = 113.07(3)°, V = 408.51(2) Å(3). The other structures are similar and consist of one-dimensional trans edge-shared distorted octahedral chains running along the b-axis. The vanadate groups bridge across edges of their tetrahedra. Structural analysis of the Ba2Mn(VO4)2(OH) analogue yielded a new understanding of the Jahn-Teller effect in this structure type. Raman and infrared spectra were investigated to observe the fundamental vanadate and hydroxide vibrational modes. Single-crystal temperature-dependent magnetic studies on Ba2V(VO4)2(OH) reveal a broad feature over a wide temperature range with maximum at ∼100 K indicating that an energy gap could exist between the antiferromagnetic singlet ground state and excited triplet states, making it potentially of interest for quantum magnetism studies.
authors.affiliation: †Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, South Carolina 29634-0973, United States.
authors.forename: Liurukara D
authors.initials: LD
authors.lastname: Sanjeewa
authors.forename: Michael A
authors.initials: MA
authors.lastname: McGuire
authors.forename: Vasile O
authors.initials: VO
authors.lastname: Garlea
authors.affiliation: †Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, South Carolina 29634-0973, United States.
authors.forename: Longyu
authors.initials: L
authors.lastname: Hu
authors.affiliation: †Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, South Carolina 29634-0973, United States.
authors.forename: George
authors.initials: G
authors.lastname: Chumanov
authors.affiliation: †Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, South Carolina 29634-0973, United States.
authors.forename: Colin D
authors.initials: CD
authors.lastname: McMillen
authors.affiliation: †Department of Chemistry and Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson, South Carolina 29634-0973, United States.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Kolis