A metastable phase alpha-FeSi2 was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on alpha-FeSi2 (111) thin films, while the bulk material of alpha-FeSi2 is metallic and nonmagnetic. The transport property of the films renders two different conducting states with a strong crossover at 50 K, which is accompanied by the onset of a ferromagnetic transition as well as a substantial magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of alpha-FeSi2 obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding sheds light on achieving ferromagnetic semiconductors through both their structure and doping tailoring, and provides an example of a tailored material with rich functionalities for both basic research and practical applications. ; ISI Document Delivery No.: CF0UR Times Cited: 0 Cited Reference Count: 38 Cao, Guixin Singh, D. J. Zhang, X. -G. Samolyuk, German Qiao, Liang Parish, Chad Jin, Ke Zhang, Yanwen Guo, Hangwen Tang, Siwei Wang, Wenbin Yi, Jieyu Cantoni, Claudia Siemons, Wolter Payzant, E. Andrew Biegalski, Michael Ward, T. Z. Mandrus, David Stocks, G. M. Gai, Zheng Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy; U.S. DOE, Office of Basic Energy Sciences, Materials Sciences and Engineering Division; U.S. DOE [DE-SC0002136] This research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences (Z. G., G. C., X.-G. Z., L. Q., M. B., E. A. P.), U.S. Department of Energy. Part of this effort was supported by the U.S. DOE, Office of Basic Energy Sciences, Materials Sciences and Engineering Division (D. J. S, G. M. S., T. Z. W., G. M. S., Y. Z., C. P.), and under U.S. DOE Grant No. DE-SC0002136 (H. G., W. W.). Amer physical soc College pk