Effect of Ca doping level on the laser-induced voltages in tilted La1−x Ca x MnO3 (0.1 ≤ x ≤ 0.7) thin films

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2014-03, Vol.114 (4), p.1075-1078
• Main Authors: Ma, Ji, Theingi, Mya, Zhang, Hui, Chen, Qingming, Liu, Xiang
• Format: Article
• Language: English
• Subjects: Anisotropy; Coefficients; Doping; Electric potential; Excimer lasers; Pulsed laser deposition; Thin films; Voltage
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-014-8240-7

Tilted La1-x Ca x MnO3 (0.1 less than or equal to x less than or equal to 0.7) thin films have been grown on vicinal cut LaAlO3 (100) substrate by pulsed laser deposition. The laser-induced voltage effect was studied at room temperature with the KrF excimer laser using as the thermal source. The relationships between Ca doping level and voltage signal, response time and anisotropy Seebeck coefficient were established. The voltage signal and anisotropy Seebeck coefficient increase at first with increasing Ca doping level, reach a maximum at the same Ca content around x = 0.5, and then decrease. The respond time decreases with the Ca concentration increasing, and changes very little after x = 0.5. The figure of merit F m was also the largest at this doping level, indicating a potential good performance of the photodetector devices. The variation of intrinsic structural and transport anisotropy induced by the change of Ca concentration has been proposed to account for the different LIV effects observed in LCMO thin films.