Co5/3Nb1/3BO4: A new cobalt oxyborate with a complex magnetic structure

• Published in: Journal of magnetism and magnetic materials 2021-09, Vol.534, p.168056, Article 168056
• Main Authors: Kazak, N.V., Belskaya, N.A., Moshkina, E.M., Bezmaternykh, L.N., Vasiliev, A.D., Bartolome, J., Arauzo, A., Velikanov, D.A., Gavrilkin, S.Yu, Gorev, M.V., Patrin, G.S., Ovchinnikov, S.G.
• Format: Article
• Language: English
• Subjects: Anomalies; Antiferromagnetism; Cobalt; Crystal structure; Crystals; Ferrimagnet; Magnetic anisotropy; Magnetic structure; Magnetic transitions; Magnetism; Magnetization; Single crystals; Warwickites
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2021.168056

•New oxyborate Co5/3Nb1/3BO4 was grown using the flux technique.•Crystal structure has been resolved in details.•The compound undergoes two magnetic transitions at TN1 = 27 K and TN2 = 14 K. Needle-shape single crystals of Co5/3Nb1/3BO4 warwickite were grown using the flux technique. X-ray diffraction measurements have revealed an orthorhombic structure (Sp. Gr. Pbnm) where the octahedral M1 site is occupied by a mixture of Co2+/Nb5+ ions and the M2 site is exclusively filled by Co2+ ions. Using dc magnetization measurements it was established that the new material undergoes two magnetic transitions: an antiferromagnetic transition at TN1 = 27 K and a ferrimagnetic one at TN2 = 14 K, below which a hysteresis cycle opens. Both magnetic transitions are marked by anomalies in the specific heat. High magnetic anisotropy with c-axis as a hard magnetization direction was detected.