Solid state studies on Bi1.7−xHgxV8O16 (x ≤ 0.4) and magnetic properties of alkali metal inserted AxBi1.7V8O16 (A = Li and Na) hollandite type phases

The effect of substitution of ‘Hg’ at the Bi-site in Bi1.7V8O16 on the phase formation and electrical properties has been studied. In Bi1.7−xHgxV8O16, single phase formation is achieved only for x ≤ 0.4 and all the phases crystallize in tetragonal structure. The dc electrical resistivity studies indicate that all the mercury substituted single phase compounds Bi1.7−xHgxV8O16 are electrically semiconducting and the room temperature resistivity values increase with increasing mercury content. Alkali metals like lithium and sodium have been inserted successfully into the tunnels of Bi1.7V8O16. The lithium intercalated phase Li2.7Bi1.7V8O16 shows antiferromagnetic ordering, whereas the sodium intercalated phase NaBi1.7V8O16 exhibits Pauli paramagnetic like behavior down to 4.5 K.