Ni-Fe alloy films of about 100 nm in thickness were deposited on MgO(001) substrates at 250 degrees C by d.c. plasma sputtering at 2.5 kV in pure Ar gas by applying a Ni0.3Fe0.7(Invar) or Ni0.2Fe0.8 target. A d.c. bias voltage V-s between O and -180 V was applied to the substrate during deposition. The structure and composition of the films were investigated by X-ray photoelectron spectroscopy (XPS), and by cross sectional transmission electron microscopy (XTEM). The resistance, its temperature coefficient TCR (150 to 300K) and saturation magnetization 4 pi Ms at 300 K were measured as a function of V-s. With the use of Ni0.3Fe0.7 target, Ni1-xFex films with x between 0.68 +/- 0.03 and 0.73 +/- 0.03, can be prepared where x was weakly dependent on V-s. The film is epitaxially grown mainly with FCC-NiFe(001)[010] parallel to MgO(001)[010] accompanied with the initial thin layer of about 5 to 10 nm in thickness with BCC-NiFe(001)[110] parallel to MgO(001)[100] at the interface at V-s values studied. Maximum TCR and minimum resistance are observed between V-s = - 120 to similar to 160 V. 4 pi Ms takes greater value at V-s greater than or equal to 120 V. In the case of Ni0.2Fe0.8 target at V-s = -120 V-s Ni1-xFex films with x = 0.80 +/- 0.03 are entirely grown in a BCC structure with NiFe(001)[110] parallel to MgO(001)[100].