While there have been some reports about preparing β-W with chemical methods such as hydrogen reduction reaction, almost all the reported β-W in the recent thirty years are prepared through sputter deposition, an atom-by-atom physical vapor deposition (PVD) technique.  In the sputter deposition, a tungsten target is bombarded with ionized gas molecules (usually Ar), causing the tungsten atoms to be “sputtered” off into the plasma. These vaporized atoms are then deposited when they condense as a thin film on the substrate to be coated. The formation of β-W through sputter deposition depends on the base pressure, Ar pressure, substrate temperature, impurity gas, deposition rate, film thickness, substrate type, etc. It has been widely observed that oxygen or nitrogen gas flow can assist and is necessary for the formation of β-W, but recently there have also been reports on preparing β-W without putting into any impurity gas during deposition.