Pressure-induced ferromagnetism in open structure alkali metals from first principles

Magnetic properties of heavier alkali metals K, Rb, and Cs in simple cubic and simple hexagonal structures at ambient and elevated simulated uniform hydrostatic pressure have been investigated using first-principles density-functional theory. The calculations exhibit the occurrence of both ferromagnetism enhancement and collapse as pressure increases and illuminate that the spin polarized interstitial electron blobs are formed by both s and p electrons. The distortion and nesting of the Fermi surface is also presented with increasing pressure.