A method forms an indium antimonide layer by a sequential evaporation for use as a magnetic sensing material having high electron mobility. The method includes the steps of: (a) preparing a substrate; (b) pre-heating the substrate (c) depositing an antimony layer on top of the substrate; (d) forming an indium layer on top of the antimony layer to thereby obtain a sequentially deposited layer, wherein the sequentially deposited layer includes the antimony and the indium layers; (e) providing a protection layer on top of the sequentially deposited layer; and (f) heat treating the sequentially deposited layer to force inter-diffusion of antimony and indium, thereby producing the indium antimonide layer.