Pulsed laser deposited na_(0.5)K_(0.5)NbO_3 thin films

摘要

Na_(0.5)K_(0.5)NbO_3 films have been grown onto polycrystalline Pt_(80)Ir_(20) substrates at two different regiemws: high (approx 400 mTorr) and low (approx 10 mTorr) oxygen pressure. FIlms grown at high oxygen pressure have been found to be soingle phase and highly c-axis oriented. The concept of discriminated thermalization has been developed to explain the dynamics of the laseer ablation process and to find reliable pulsed laser deposition (PLD) processing coditions. The phenomenon of self assembling of Na_(0.5)K_(0.5NbO-3 films along [001] direxction has been observed. On the other hand, films grown at low oxygen pressure have been found to be mixed phase of ferroelectric Na_(0.5)K_(0.5)NbO_3 and paraelectric potassium niobates. Superparaelectric behavior has been observed in these fims: 5