Approximate kappa-state solutions of the Dirac equation in spatially dependent mass for the Eckart potential including the Yukawa tensor interaction

We investigate the analytical approximation to arbitrary kappa-state solutions of the Dirac equation with the position-dependent mass particle in the Eckart potential including the Yukawa tensor interaction in the framework of a parametric Nikiforov-Uvarov method. By taking a proper approximation to deal with the centrifugal term, the analytical relativistic energy eigenvalues and the corresponding normalized two-spinor components of the wave function are obtained in closed form. The relativistic and non-relativistic bound state solutions for some special cases, such as the Hulthen potential and the generalized Morse potential, are easily obtained from our general solution.