An active material electronic device with a containment layer. The device includes an active chalcogenide, pnictide, or phase-change material in electrical communication with an upper and lower electrode. The device includes a containment layer formed over the active material that prevents escape of volatilized matter from the active material when the device is exposed to high temperatures during fabrication or operation. The containment layer further prevents chemical contamination of the active material by protecting it from reactive species in the processing or ambient environment. Once the containment layer is formed, the device may be subjected to high temperature or chemically aggressive environments without impairing the compositional or structural integrity of the active material.