Structural Phase Transitions in the Ferromagnetic Vanadium Oxide NaV6O11

Effect of Iron Substitution on the Structural, Electric, and Magnetic Properties inR-Type PbFexV6−xO11, a Frustrated System

“…R blocks were first isolated in BaFe Te O with space group P6 /mmc at room temperature (4). The same space group is found at room temperature for all other AV O compounds investigated to date (5). In PbV O , the Pb> 6s lone pair gives rise to the noncentrosymmetric P6 mc space group.…”

Phase transitions and electrical transport in the mixed-valence V2+/V3+ oxide BaV10O15

“…A number of materials with structures derived from magneto-plumbite have been reported with composition MV 6 O 11 (M ¼ Na; K; Sr; Pb) and hollanditebased phases, Ba x V 8 O 16 and BaV 10Àx O 17 , for example, [13][14][15][16][17][18]. NaV 6 O 11 is the best studied member of this series and shows a range of interesting properties including crystallographic phase transitions and metallic weak ferromagnetism [19][20][21]. A partial form of magnetic frustration is also known, as one set of V sites (out of three) in the crystal structure forms a Kagome lattice [22].…”

Integrated-Optic Add/Drop Multiplexing of Free-Space Waves for Intra-Board Chip-to-Chip Optical Interconnects

“…Since the discovery of its anomalous resistivity [2,3], magnetic character [3], and structural phase transitions [4], the compound has received wide interest.…”

“…At T H = 243 K, NaV 6 O 11 shows a second-order P6 3 /mmc → P6 3 mc structural phase transition, in which the mirror plane perpendicular to [001] is lost [4]. In the lowsymmetry phase, the V(1)O 6 octahedra form trimers with a regular triangular shape.…”

“…At 80 K, NaV 6 O 11 undergoes a second structural phase transition to the orthorhombic phase Cmc2 1 (Z = 4) [4,8,9], in which the V(1)O 6 trimers distort into isosceles triangles. Although space group Cmc2 1 is a minimal subgroup of P6 3 mc and the experimental observations suggested a second-order character of the phase transition [4], Iwata and Ishibashi pointed out that the transition must be of the first order to fulfill the Landau condition [8].…”