English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The pressure-volume equation of state (EoS) of single-crystal MgO has been studied in diamondanvil cells loaded with helium to 118 GPa and in a non-hydrostatic KCl pressure medium to 87 GPa using monochromatic synchrotron X-ray diffraction. A third-order Birch-Murnaghan fit to the nonhydrostatic P-V data (KCl medium) yields typical results for the initial volume, V 0  = 74.698(7) Å 3 , bulk modulus, K T0  = 164(1) GPa, and pressure derivative, K′ = 4.05(4), using the non-hydrostatic ruby pressure gauge of Mao et al. (1978). However, compression of MgO in helium yields V 0  = 74.697(6) Å 3 , K T0  = 159.6(6) GPa, and K′ = 3.74(3) using the quasi-hydrostatic ruby gauge of Mao et al. (1986). In helium, the fitted equation of state of MgO underdetermines the pressure by 8% at 100 GPa when compared with the primary MgO pressure scale of Zha et al. (2000), with K T0  = 160.2 GPa and K′ = 4.03. The results suggest that either the compression mechanism of MgO changes above 40 GPa (in helium), or the ruby pressure gauge requires adjustment for the softer helium pressure medium. We propose a ruby pressure gauge for helium based on shift of the ruby-R 1  fluorescence line (Δλ/λ 0 ) and the primary MgO pressure scale, with P (GPa) = A/B{[1 + (Δλ/λ 0 )] B  - 1}, where A is fixed to 1904 GPa and B = 10.32(7).

Compression of single-crystal magnesium oxide to 118 GPa and a ruby pressure gauge for helium pressure media