1. A memory cell comprising: a first electrode; a second electrode; a semiconductive material intermediate the first and second electrodes and comprising a plurality of mobile dopants configured to move within the semiconductive material as a result of a voltage being applied to the first and second electrodes; and a barrier material intermediate the semiconductive material and one of the first and second electrodes, and wherein the barrier material is impervious to movement of the mobile dopants from the semiconductive material to the barrier material.