Pulsed laser deposition of mixed valence manganite artificial superstructures

The magnetic structural and magnetotransport properties are studied in a series of [La2/3Ca1/3MnO3/La1/3Ca2/3MnO3]15 multilayers prepared by pulsed laser deposition. The La2/3Ca1/3MnO3 layers are ferromagnetic (FM) and La1/3Ca1/3MnO3 layers are antiferromagnetic (AF). The structural compatibility of the AF and FM layers permits coherent growth that favors magnetic coupling. The hysteresis loops of field cooled samples are shifted. This is attributed to the presence of an exchange biasing mechanism at low temperatures. Zero-field-cooling and field-cooling magnetic measurements reveal a blocking temperature around 70 K that is independent from the bilayer thickness, whereas the average film magnetization becomes zero at 250 K.