Emergence of exchange bias and giant coercive field enhancement by internal magnetic frustration in La0.67Sr0.33MnO3 thin films

•La0.67Sr0.33MnO3 films were grown on SrTiO3 substrates.•Defects were introduced using alumina mask and Oxygen ion irradiation.•Oxygen ion irradiation creates defects in spatially confined regions of the LSMO film.•Irradiation reduces the ferromagnetic ordering temperature and total magnetization.•Giant coercivity enhancement and appearance of exchange bias below 50 K were observed.