Raman-Scattering Study of Doping Effects on the Structural Phase Transitions under Hydrostatic Pressures in CuGeO₃

Effect of doping and counterdoping on high-pressure phase transitions of silicon

“…From Vegard's law that the Ge induced lattice expansion can compensate the lattice contraction caused by B doping because the atomic radius of Ge ͑1.22 Å͒ is larger than that of Si. 6,23 Since the concentrations of the dopants are ultralow compared with the density of Si ͑5 ϫ 10 22 atoms/ cm 3 ͒, i.e., only one B atom in several thousands of Si atoms. The strain compensation in B/Ge codoping Si most likely due to the local volume compensation by introducing Ge atoms as the neighbors of B atoms to form Ge-B clusters.…”