Work function of e-beam deposited Lanthanum hexaboride film

Lanthanum hexaboride (LaB6) is a low work function material. When coated on conventional field emission tips, it can significantly enlarge the field emission current of the tips. To determine its work function, LaB6 films were deposited through e-beam deposition. It is found that the films with low oxygen content were (100) preferentially oriented. The work function was measured by thermal emission and field emission independently, yielding a value of 2.67 eV and 2.91 eV, respectively, suggesting that e-beam deposited LaB6 films preserve the low work function of bulk LaB6.