A memory cell can include a phase change material layer and a first electrode layer adjacent to the phase change material layer and having a phase change material layer side oriented toward the phase change material layer and a bit line side opposite the phase change material layer side. A carbon nitride layer can be on the bit line side surface of the first electrode layer. In some examples, a nonconductive separator material can have a word line end and a bit line end, and can have a portion contacting the phase change material layer. The bit line end surface of the nonconductive separator material can be at least partially free of contact with the carbon nitride layer.