A magnetic head having read and write elements is provided according to one embodiment. The head includes a substrate. An undercoating is coupled to the substrate. The undercoating has a preferred thickness of between about 1.5 and 0.5 microns or less in a direction perpendicular to the planar surface of the substrate engaging the undercoating. Preferably, the undercoating is reduced to a desired thickness during fabrication using chemical mechanical polishing. The undercoating is constructed of a material having a thermal conductivity greater than that of amorphous Al₂O₃. An electric contact pad is operatively coupled to a layer positioned between the pad and the undercoating. Electric contact pads of read and write elements are preferably separated from the undercoating by insulation planarization layers. A write element is coupled to the undercoating. The write element has an electrically conductive coil. The new thinner and more thermally conductive undercoating allows more heat to transfer through it from the write element to the substrate.