Magnetic properties of ludwigite Mn2.25Co0.75BO5

Popov, D., V; Gavrilova, T. P.; Gilmutdinov, I. F.; с соавторами. JURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS. https://doi.org/10.1016/j.jpcs.2020.109695O

Needle-shape single crystals of Mn2.25Co0.75BO5 ludwigite were synthesized by the flux technique and investigated by means of X-ray diffraction, static magnetic susceptibility and specific heat measurements. Magnetization and specific heat experiments showed the presence of ferrimagnetic ordering near T $_{N} ≃ 61$ K. Below this temperature the magnetic properties demonstrated the angular dependence and the high magnetic hardness in a magnetic field applied perpendicular to the crystallographic c axis, which is similar to other cobalt-containing ludwigites. The effective magnetic moment per magnetic ion $4.8 μ_{B}$ was calculated from the paramagnetic data. Analysis of the phonon contribution to the specific heat allowed to distinguish the magnetic contribution $C_{M}$ , which has two features. One of which was observed at $T_{N}$ and can be attributed to strong exchange interactions between spins of magnetic ions. The second one at T $=$ 11.6 K is due to the effect of the ligands crystal field on a magnetic ion with $S > 1 ∕ 2$ .