Ni films 200 nm thick are deposited on GaAs(001) substrates at 280 degrees C by d.c. plasma sputtering at 2.5 kV in pure Ar gas. A d.c. bias voltage V-s from 0 to - 180 V is applied to the substrate during deposition. The effect of V-s on the film growth is investigated by measuring TCR from 150 to 300 K, and resistance at 300 K, also by AES, XTEM, and RHEED observations. Minimum resistance and maximum TCR are observed at V-s between - 80 and - 100 V. The Ni film is polycrystalline with a [001] texture, while an As2Ni thin layer is grown penetrating into the GaAs substrate with As2Ni[111]\\GaAs[111] and As2Ni[011]\\GaAs[011]. The Ni film, composing of uniformly grown grains, is obtained with a higher value of TCR at V-s= -80 V.