Zur Stabilisierung der Oxidationsstufe M^IV im Ni₅MB₂O₁₀‐Typ

Abstract

Mit Hilfe von Schmelzflußreaktionen wurden Einkristalle der bisher unbekannten Verbindungen Ni5VB2O10 (I) und Ni5MnB2O10(11) erhalten. Beide sind isotyp zu Ni5TiB2O10, (Raumgruppe D2h9–Pbam, Z = 2; (I): a = 9,183; b = 12,189; c = 2,989 Å; (II): a = 9,130; b = 12,164; c = 2,970 Å). Ni2+ und V4+ bzw. Mn4+ besetzen eine der Metallpunktlagen statistisch. Die partielle Unordnung in der Metallverteilung wird durch Berechnung des Coulombterms der Gitterenergie bestätigt.

Magnetization pole reversal of ferrimagnetic ludwigites Mn3−xNixBO5

“…The unique compound of this family with x = 2.5 was synthesized by Bluhm et.al. [7], but its magnetic properties have not been studied. Here, we report the magnetic measurement data for the samples with the low (x 1 = 0.5) and high ( In the prepared fluxes, the phase crystallizing within a sufficiently wide (about 40°C) high-temperature range was Mn 3−x Ni x BO 5 with the ludwigite structure.…”

Synthesis and Crystal Structure of the First Fully Characterized Vanadoborate Na3[B6O9(VO4)]

“…However, no structure of any hydrated or anhydrous alkaline vanadoborate has been established, which may con"rm the proposed formula; only some unindexed X-ray di!raction powder patterns were given, leaving a serious doubt about their existence. The compounds Ni VBO (11) and Ni VB O (12), which belong to the ludwigite type (M, M 2 ) O BO , where the metal ions (M, M 2 ) can be dior trivalent, are not considered because vanadium has an oxidation state di!erent from "ve. We have undertaken the study of sodium vanadoborates starting from the results published on the NaBO }V O binary system (7); two compounds were described: 3Na…”

Magnetism and structure of Ni2MnBO5 ludwigite

“…This model was not restrained, and Ni/Mn occupation ratios were refined for all four Mn/Ni sites. Refinement showed that final chemical formula Ni 1.6(1) Mn 1.4(1) BO 5 is close to proposed, and the structure proved to be isostructural to Ni 2.5 Mn 0.5 BO 5 [9].…”