Room-temperature magnetoresistance of nanocrystalline Ni metal with various grain sizes V. A. Isnaini, T. Kolonits, Zs. Czigány, J. Gubicza, S. Zsurzsa, L. K. Varga, E. Tóth-Kádár, L. Pogány, L. Péter and I. Bakonyi Eur. Phys. J. Plus, 135 1 (2020) 39 Published online: 10 January 2020 DOI: 10.1140/epjp/s13360-019-00067-2