In the present work, we report the phase transition from crystalline to amorphous (topological disorder) of NiSO₄·6H₂O (NSH) for which impedance spectroscopic and differential scanning calorimetric (DSC) techniques have been utilized to understand the changes in a better way thereby the electrical and thermal properties could be identified. According to the observed dielectric properties, the crystalline NSH has a low dielectric constant and low electrical conductivity whereas both of these values are high for the obtained amorphous state. DSC thermograms provide crystal clear details for the cause of the witnessed changes wherein the melting point region changes for both the crystalline and the amorphous samples. The values of magnetization for crystalline and amorphous samples are found to be 0.7339 and 2.070 emu/g, respectively. Because of the effective switchability between crystalline and amorphous states, the NSH crystal is suggested for the applications of sensors and dielectric switches.