ABSTRACT While the temperature of X-ray corona (kTe) in active galactic nuclei (AGNs) is known for many sources, its variation if any limited to a handful objects. This part due requirement good signal-to-noise spectra, covering wide range energies. We present here results on spectral analysis 18 Seyferts, having more than one epoch observations look kTe. The data total 52 epochs these AGNs wer...
