Electronic Journal of Differential Equations, Vol. 2012 (2012), No. 62, pp. 1-14. Title: Sufficient conditions on diffusivity for the existence and nonexistence of stable equilibria with nonlinear flux on the boundary Authors: Janete Crema (USP, S. Carlos, S. P., Brasil) Arnaldo Simal do Nascimento (Univ. Federal de Sao Carlos, Brasil) Maicon Sonego (Univ. Federal de Sao Carlos, Brasil) Abstract: A reaction-diffusion equation with variable diffusivity and nonlinear flux boundary condition is considered. The goal is to give sufficient conditions on the diffusivity function for nonexistence and also for existence of nonconstant stable stationary solutions. Applications are given for the main result of nonexistence. Submitted June 27, 2011. Published April 12, 2012. Math Subject Classifications: 35J25, 35B35, 35B36. Key Words: Reaction-diffusion equation; stable stationary solutions; variable diffusivity; implicit function theorem.