Superconducting Transition Temperature and Magnetic Susceptibility in the Solid Solution Nb1-xMoxSe₂ and Nb1-yTiySe₂

The superconducting transition temperature T c and magnetic susceptibility χ in the solid solution Nb 1- x Mo x Se 2 and Nb 1- y Ti y Se 2 were measured T c and χ in the solid solutions decrease as composition x or y increases. The measured variations of T c and χ are consistently interpreted by the variation of the Fermi density of states. The electronic density of states curve for these compounds was obtained from the experimental data using the rigid band model. It was found that a sharp peak exists in the density of states centered at the Fermi energy of NbSe 2 . This result is in close agreement with the calculation of the band density of states for NbSe 2 by Mattheiss.