MnBi hard magnetic films optimised through the correlation between resistivity, morphology and magnetic properties

•Rare earth-free MnBi permanent magnets were successfully fabricated by pulsed laser. deposition.•The changes in their nanostructure have been monitored by measuring the temperature. dependence of their resistivity.•Accordingly, heat treatments to 300 °C originated the LT-MnBi phase with permanent. magnets characteristics.•An optimum deposition geometry was found, that maximized the energy product of our MnBifilms.•An easy magnetization direction perpendicular to the film plane was evidenced by VSM.