Über Oxidpnictide: Zur Kenntnis von A₂Mn₃B₂O₂ mit A = Sr, Ba und B = As, Sb, Bi / On Oxidpnictides: Preparation and Crystal Structure of A₂Mn₃B₂O₂ with A = Sr, Ba and B = As, Sb, Bi

Abstract

<jats:p>Five new oxidpnictides have been prepared and structurally characterized. They crystallize in the tetragonal system, I4/mmm, with the following constants: </jats:p><jats:p>Sr<jats:sub>2</jats:sub>Mn<jats:sub>3</jats:sub>As<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>: a = 416 ± 1 pm, c = 1884 ± 4 pm, c/a = 4.529, </jats:p><jats:p>Ba<jats:sub>2</jats:sub>Mn<jats:sub>3</jats:sub>As<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> : a = 424.8 ± 0 5 pm, c = 1977 ± 3 pm, c/a = 4.654, </jats:p><jats:p>Sr<jats:sub>2</jats:sub>Mn<jats:sub>3</jats:sub>Sb<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> : a = 426.2 ± 0.4 pm, c = 2011 ± 2 pm, c/a = 4.718, </jats:p><jats:p>Ba<jats:sub>2</jats:sub>Mn<jats:sub>3</jats:sub>Sb<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> : a = 436.7 ± 0.5 pm, c = 2078 ± 2 pm, c/a = 4.758, </jats:p><jats:p>Sr<jats:sub>2</jats:sub>Mn<jats:sub>3</jats:sub>Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> : a = 428 ± 1 pm, c = 2055 ± 5 pm, c/a = 4.801. </jats:p><jats:p>Mn- and As(Sb,Bi) atoms form tetragonal pyramids, connected by common edges in the basis to two-dimensional sheets. These sheets are separated by double layers of Sr atoms, in which Mn and O atoms are located forming MnO<jats:sub>4</jats:sub> square plane nets.</jats:p>

Physical properties and electronic structure ofSr2Cr3As2O2containingCrO2Jiang1, Bao2, Zhai3 et al. 2015Phys. Rev. B317530View full textAdd to dashboardCite

“…However, previous efforts to synthesize the target materials were unsuccessful 8 , which is possibly because Cu (Fe) more easily bonds with X (O) according to the "Hard and Soft Acids and Bases" concept 7,9 . In fact, a similar compound, Sr 2 Mn 3 As 2 O 2 (2322), which contains alternating MnO 2 sheets and Mn 2 As 2 layers, was reported earlier in 1979 10 . Later in 1990s, a series of 2322-type materials were synthesized and characterized [11][12][13][14][15][16][17][18] , presumably due to the structural similarity with cuprate superconductors.…”

Chemistry of layeredd-metal pnictide oxides and their potential as candidates for new superconductors

“…Because of this unique mixed anionic environment, pnictide oxides tend to have characteristic structures that are rarely observed in simple oxides. For example, some of the pnictide oxides crystallize in the structure which consists of alternating fluorite-(or ThCr 2 Si 2 -) type d-metal (transition metal or group 12 metal) pnictide layers and LaNiO 2 -(or square-planar [CuO 2 ] 2− -) type metal oxide layers interspersed with alkaline-earth metals [5][6][7][8][9][10][11].…”

“…Such investigations of the structure-property relationships in the layered d-metal pnictide oxides began (2) 9.125(6) [32] intensively in the 1990s to search for interesting and practical properties such as superconductivity [5][6][7][8][9][10][11][12][13][14][15][16]. As a matter of fact, the anomaly reminiscent of a CDW (charge-density wave) / SDW (spin-density wave) was discovered in one of the layered d-metal pnictide oxide families, Na 2 Ti 2 Pn 2 O (Pn = As, Sb), and generated much interest [12][13][14][15][17][18][19][20].…”

Physical properties of Ba2Mn2Sb2O single crystals

“…13,16,17 The magnetic moment due to the Mn in edge-shared MnPn 4 orders antiferromagnetically at low temperatures. This motivates us to study Ba 2 Mn 2 Sb 2 O, which has a double layered MnSb 3 O tetrahedra edge shared in the ab-plane, but corner shared along the c-direction (see Fig.…”