Equation of state of orthorhombic boron, -B28

Quasi-hydrostatic compression of orthorhombic boron, γ-B28, has been studied in the neon pressure medium up to 65 GPa at room temperature using angle-dispersive X-ray powder diffraction with synchrotron radiation. A fit of the experimental p – V data to the Vinet equation of state yields the values of the bulk modulus, B 0 , of 237(5) GPa with its first pressure derivative, B 0 ′ , of 2.7(3). The compression is found to be anisotropic with highest compressibility along a -axis.