In this paper nanocrystalline diamond films have been deposited initially through a novel technique periodic magnetic field (PMF) (magnetic field B = B-0 sin omega t) assisted hot filament chemical vapor deposition. The effect of the increasing angular frequency (omega) on diamond film deposition was investigated. SEM and Raman spectroscopy were used to characterize film. It was found that higher co was in favor of nano-diamond film growth. Field emission results show that the turn-on electric field of the nano-diamond film deposited at omega = 20,000 rpm was 2.9 V/mu m, and its current density reached 32.7 mu A/cm(2) measured at an applied field 6.5 V/mu m. (C) 2015 Elsevier B.V. All rights reserved.