The melt structure evolution under the action of the low-frequency axial vibration control (AVC) technique was studied in situ by Raman spectroscopy for several complex chemical compound melts: sodium nitrate, margarine acid, paraffin mixture (C-17-C-20). The measurements were conducted in the temperature range from the melting point up to 60 degrees C above. Comparison of crystallization heats for AVC activated and steady melts with melting heats of AVC-CZ and conventional CZ produced powders allowed to propose the energy diagram of NaNO3 states for activated and non activated melts and crystals based on DTA, XRD, DSC and Raman experimental data. (C) 2014 Elsevier B.V. All rights reserved.