Bulk modulus of CaO under high pressure up to 65 GPa

Abstract

In the present study we used some equilibrium experimental data reported by Mammon et al. (Geophysical Research Letters, Vol. 8, No. 2, pp. 140-142) to investigate the effect of high pressure up to 65 GPa on the bulk modulus of calcium oxide (CaO) material. We used the Vinet’s equation of state (EOS) model. The fit of the bulk modulus as a function of pressure p obeys the 2nd order polynomial expression: B = 115.37 + 3.84 p - 7.25 x 10-3 p2 (where both B and p are expressed in GPa). Our results are analyzed and compared with other theoretical data of the literature. Similar behavior for the bulk modulus versus pressure was observed for some other materials with different crystallographic structures from the literature, which commonly increases with increasing pressure. We estimate also the Debye temperature θD of our material of interest using the experiential lattice parameter and elastic constants measured at normal conditions by Speziale et al. (Journal of Geophysical Research, Vol. 111, (2006), pp. B02203 (12 pages)). Our obtained value (670.1 K) is in good agreement with other data of the literature.

Debye temperature of CaO under high pressure up to 65.2 GPa

“…The results are consistent with the values reported for CdSe, Cd0.75Cr0.25Se, ZnS, and Zn0.75Cr0.25S materials [29]. Compared with the bulk modulus B at equilibrium, our obtained data of B using the experimental elastic constants measured by Speziale et al [6] are somewhat larger than both the ab initio plane-wave pseudopotential DFT method [2] and semi-empirical approach [5] at high pressure. The knowledge of the sound velocity can play in important role in material science [30].…”

“…Our obtained values of the bulk modulus B and the shear moduli GV, GR, and G of CaO material are tabulated in Table 1, along the results reported in Ref. [5] found at equilibrium. Our obtained values of the bulk modulus B are also traced in figure 1, along other data of the literature [2,5].…”

“…[5] found at equilibrium. Our obtained values of the bulk modulus B are also traced in figure 1, along other data of the literature [2,5]. We observe that the bulk modulus B of CaO compound increases with increasing pressure up to 65.2 GPa.…”

“…The intent of this paper is to present and investigate the effect of high pressure up to 65.2 GPa on the bulk modulus, aggregate shear modulus, elastic wave velocities, and Debye temperature of CaO material using only the experimental data reported by Speziale et al [6]. Our obtained results are analyzed and compared with other theoretical data [2,5] of the literature.…”

“…They found that the band gaps of SrO and CaO compounds decrease quasilinearly with increasing pressure, while that of MgO increases with increasing pressure. Batra et al [4] have performed a comparative investigation of the structures, stabilities, and properties of some alkaline earth metal oxides ((MgO), (CaO)𝑛, (SrO)𝑛, and (BaO)𝑛) nanoclusters using density functional theory, while Daoud and Rekab-Djabri [5] have investigated the pressure dependence of the bulk modulus of CaO material up to 65 GPa using semi-empirical approach. Using both the powder X-ray diffraction (XRD) and the Brillouin spectroscopy (Single-crystal Brillouin scattering) techniques, Speziale et al [6] have investigated the high pressure effect up to 65.2 GPa on the several mechanical properties of CaO material.…”