Accurate measurement of the cross-section of the 12 C(α, γ) 16 O reaction is very important in nuclear astrophysics. Enriched 12 C targets prepared with the high energy vibrationl powder plating [HIVIPP] method for this purpose have been used successfully. Initially, however, the 12 C deposits for studying this small cross-section partially peeled from their Au backings when irradiated with beam currents≥2 times the 7μA pulsed α-beam used previously. This problem was solved when the amorphous 12 C powders were converted to graphite by heat-treatment in a high-temperature furnace. We investigated powder heat treatments at temperatures of 2600–3500°C to reveal, which conditions resulted in uniform and highly adhesive depositions on Au backings.