STM studies of Co_xNbSe₂and Mn_xNbSe₂

Cobalt and Manganese intercalated NbSe2 single crystals have been synthesized and characterized by DC magnetization and scanning tunnelling microscopy (STM) at low temperatures. We observed a pronounced peak effect in magnetization for both Co and Mn intercalated samples that we further investigated by low temperature STM. A structural phase transition of the vortex lattice (VL) has been observed for applied magnetic fields corresponding to the peak in magnetization.