Cubic GaCrN layers are grown on MgO(001) substrates at 350-700 degrees C, by plasma-assisted molecular beam epitaxy. Substrate temperature dependences of their structural and magnetic properties were systematically studied. It is found that the solubility limit of Cr atoms in cubic GaCrN is dramatically improved by the low temperature (350 degrees C) growth, though crystalline quality becomes poorer. It is also observed that the magnetic ordering increases with Cr content in the low Cr content region, but after showing highest ordering it decreases in the high Cr content region. The Cr content range showing fierromagnetic behavior increases with lowering substrate temperature. However, the magnetization vs. magnetic field curve shows "emaciated" hysteresis for the low temperature grown samples. (C) 2007 Elsevier B.V. All rights reserved.