A data storage medium such as a disc for a disc drive having a data signal layer configured for providing a data signal and a servo signal layer that includes first material a second materials having thermal characteristics that are distinct from one another. The first material and second material define at least one signal feature for providing a modulating servo signal based upon the variation of thermal properties in the servo signal layer.The first material may define spaced features of a servo pattern such as grooves and pits and the second material may fill the grooves and pits or other features. The intersection of the first and second material may provide a distinct thermal transition so that when the medium, typically a disc, is rotated around an axis, the servo features generate a thermo signal having a frequency proportional to the spacing between the signal features and an amplitude that is a function of the thermal properties of the first material and the second material.The modulating servo signal may be detected by a thermal sensor which may include a magneto resistive element. The thermal system may be configured so that a data element detects both a servo signal and a data signal. The output from the data element may be processed to isolate the servo signal and data signal. Alternatively, the data signal and thermally-detectable servo signal may be detected by separate elements.