Thermal stability and thermal expansion of recovered rs-ZnO samples in the range of 300-1000 K at ambient pressure have been studied in situ by synchrotron powder X-ray diffraction at the B2 beamline of the DORIS III storage ring (HASYLAB, DESY). Debye-Scherrer geometry with a rotating quartz capillary was used. The X-ray diffraction patterns were collected in the 2-70° 2θ-range (λ = 0.69797 Å) for 10 min in real time using the OBI image plate detector. A NIST powder LaB 6 (Pm-3m, a = 4.15695 Å) was used as standard for detector calibration at 300 K. X-ray diffraction experiments were performed upon stepwise heating with a step of 50 K. Sample temperature was measured with a chromel-alumel thermocouple after stabilization for 5 minutes prior to each data acquisition.