Systems in accordance with the present invention can include a tip
contactable with a media, the media including a substrate and a plurality
of cells disposed over the substrate, one or more of the cells being
electrically isolated from the other of the cells by a material having
insulating properties. One or more of the plurality of cells can include
a phase change material. The media is either grounded or electrically
connected with a voltage source such that when the tip is placed in
contact with the media and a voltage is applied to the tip, a current is
drawn through the cell over which the tip is arranged. The current is
drawn through the isolated cell at least a portion of the phase change
material within the cell beneath the tip is heated to a sufficient
temperature such that the material become amorphous in structure. The
current is then removed from the phase change material, which is quickly
cooled to form an amorphous domain having a resistance representing a "1"
(or a "0"). In an embodiment, the one or more cells can have a sidewall
structure that tapers along the depth of the cell so that the cell has a
wider cross-section near where a tip contacts the media and a narrower
cross-section near where the cell contacts one of the substrate and an
underlayer.