Synthesis of ultra-thin nanobristles of Na-Mn-O compounds and their magnetic and structural properties

Boron substituted Na_0.44MnO₂ nanorods were synthesized via conventional solid state reaction technique. Optimum synthesis temperature of the nanorods is determined as 750 °C. As the temperature increases, the nanorods start merging each other. As the boron content increases, amount of nanorods decrease due to the emergence of impurity phases. 12.5% boron substitution (x=0.25 in NaMn_2−xB_xO₄ nominal composition) into Mn site striggers the formation of ultra-thin nanobristles on the surface of the nanorods. These nanobristles disappear completely in x=0.75 sample. We attribute the formation of these nanobristles to the increase in the internal energy upon increase in the unit cell volume.