Monte Carlo simulation of magnetic phase transitions in Mn-doped ZnO

► Mn-doped ZnO is well investigated by ab-initio, but we are not aware of any studies using Monte Carlo. ► We aim to shed more light on ambiguities concerning reports of ferromagnetism in ZnO diluted by Mn. ► We use MC that gives more precise results than effective field theory that over estimates TCurie. ► We study the effect of magnetic impurities and hole carriers on the existence and nature of ferromagnetism. ► We give the exact values of carriers' concentration that perform magnetic order and those to avoid.