Lattice parameter and thermal expansion of ReO₃between 291 and 464 K

Abstract

The Bond technique was used to measure the lattice parameter of the red transition‐metal oxide, ReO3, as a function of temperature. At 298 K the lattice parameter is 3.7477 (1) Å. The thermal expansion is linear with temperature between 291 and 464 K and a linear coefficient of thermal expansion of 1.1 (1) × 10−6 K−1 was fit to the data.

X-ray absorption spectroscopy study of local dynamics and thermal expansion inReO3

“…The thermal expansion coefficient measured in the present work, α 2.6 × 10 −6 K −1 from 300 to 470 K, is larger than that measured in previous works [12,21,35,36] but comparable to the expansion recently obtained [38] for the isostructural cubic WO 3 , α 3.9 × 10 −6 K −1 between 300 and 500 K. Since no internal coordinates are necessary to describe the structure of ReO 3 , the distances between atomic positions are directly proportional to the lattice constant, and their thermal expansions are proportional to the lattice thermal expansion. However, the lack of XRD data below 300 K, in principle, prevents the comparison with EXAFS data in order to evaluate the perpendicular MSRDs according to Eq.…”

“…[35] an NTE coefficient was measured on a single crystal at low temperatures: it was −2 × 10 −6 K −1 below 100 K, then it increased rather rapidly with temperature and became positive above 340 K, up to 500 K; on the contrary, an average positive expansion coefficient was quoted in Refs. [12] and [36] from 100 to 500 K. Later, a weak positive thermal expansion was found in Refs. [21] and [37].…”

“…The presence of empty A sites permits large rotations of the ReO 6 octahedra. No evidence has been found of phase transitions at ambient pressure in the low-temperature range, up to 500 K [12]. The stability of the cubic lattice has been explained in terms of interaction between phonons and conduction electrons [13].…”

“…Until recently, the thermal expansion data for cubic ReO 3 were available from the interference [35] and XRD [12,21,36,37] measurements, showing surprisingly different trends with temperature: in Ref. [35] an NTE coefficient was measured on a single crystal at low temperatures: it was −2 × 10 −6 K −1 below 100 K, then it increased rather rapidly with temperature and became positive above 340 K, up to 500 K; on the contrary, an average positive expansion coefficient was quoted in Refs.…”

“…Over the last years, neutron and synchrotron radiation techniques (diffraction and EXAFS) available at large-scale [12] (violet line) and from Dapiaggi and Fitch [11] (filled green circles); (ii) neutron diffraction, from Chatterij et al [32] (filled black circles) and Rodriguez et al [33] (different powdered samples according to Ref. [33]: ReO 3 -a, filled red circles, ReO 3 -b, filled (red) diamonds; and ReO 3 -c, filled (red) squares); (iii) laser interferometry, from Matsuno et al [35] [(blue) stars]; and (iv) diffraction on ScF 3 , from Ref.…”