A Compact Furnace for Synchrotron Powder Diffraction Experiments up to 1800 K

A new electric furnace has been designed and fabricated for measurements of the high‐resolution synchrotron radiation powder diffraction profiles from materials at high temperatures up to 1807 K in air, suitable for the multiple‐detector system installed at the BL‐4B 2 experimental station of the Photon Factory, Tsukuba, Japan. In the present study, at 1703 K in air, the whole powder pattern of National Institute of Standard and Technology ceria powder was step scanned at a step interval of 0.004° in 2θ, by the counting time of 1.5 s/step and with a monochromatized 1.205363(5) Å X‐ray, in just 7 h. The full width at half‐maximum of the 111 reflection of the ceria was narrow (0.0139°). The δ d / d resolution of the ceria ranged from 0.058% to 0.126% at 1703 K, where d and δ d are the lattice spacing and peak width, respectively. Precise unit‐cell parameter 5.51259(1) Å and the atomic displacement parameters were refined by the Rietveld analysis of the powder data measured at 1703 K. An electron‐density map of ceria at 1703 K was obtained by the maximum‐entropy method.