Controllable synthesis and magnetic property of BiMn2O5 crystals

Abstract Uniform submicron BiMn 2 O 5 particles were prepared via a facile one-step hydrothermal route at low temperature. Bi(NO 3 ) 3 , MnCl 2 ·4H 2 O and KMnO 4 were used as starting materials; KOH as a pH adjustor and also as a mineralizer. Single-crystalline orthorhombic BiMn 2 O 5 sample with controllable morphology was obtained. The microstructure strongly depends on the molar ratio of the starting materials, KOH concentration and reaction temperature. X-ray photoelectron spectroscopy shows the existence of Mn 4+ state. Magnetic measurement indicates Neel temperature T N at 44 K. The susceptibility above T N obeys the Curie–Weiss law, χ = C /( T − θ ), with θ = −350 K. The effective paramagnetic moment μ eff = 4.66 μ B /Mn, demonstrating the coexistence of mixed Mn 3+ and Mn 4+ valences.