Quiroz Heiddy P, Galíndez E F, Dussan A
Universidad Nacional de Colombia - Bogotá, Department of Physics, Grupo de Materiales Nanoestructurados y sus Aplicaciones, Cra. 30 No. 45-03 Edificio 404 Yu Takeuchi Lab. 121C / 121B-1 Ciudad Universitaria - Bogotá, 11001, Colombia.
Heliyon. 2020 Feb 8;6(2):e03338. doi: 10.1016/j.heliyon.2020.e03338. eCollection 2020 Feb.
TiO:Co thin films on ITO (Indium-tin-oxide)/PET (Poly Ethylene Terephthalate) flexible and glass substrates were fabricated via DC magnetron co-sputtering at room temperature. The samples deposited on glass substrates were subjected to annealing processes at 473 K for 2 h to improve the crystallization of the material. Both TiO:Co/ITO/PET and TiO:Co/glass thin films exhibited excellent optical properties with more than 80% transmission in the visible region. An increase on ITO/PET surface temperature was detected during the synthesis of the samples; this variation in the ITO substrate ( 2 K) was associated to impact energetic of ion or atoms bombarded during the deposition process. X-ray diffraction measurements evidenced local phases to growth on the flexible substrate; the random distributions of Cobalt crystals into the rutile and anatase phases were associated to a crystalline lattice embedded with magnetic ions. A configuration of small grains and absence of cluster formation on the surface of thin films was observed through SEM and AFM measurements. From this topographic study and MFM measurements evidenced that surface grains were not constituted magnetic domains formation in the thin films. The ferromagnetic-like behavior was observed in a magnetization as function of field measurement by PPMS. M vs H curves at room temperature for TiO:Co/ITO/PET thin films, showed the hysteresis loop. The dipolar interaction between Cobalt ions without formation of domains were correlated to the magnetic behavior in the material, as the doping concentration is lower than 12%.
通过直流磁控共溅射在室温下在ITO（氧化铟锡）/PET（聚对苯二甲酸乙二酯）柔性基板和玻璃基板上制备了TiO:Co薄膜。将沉积在玻璃基板上的样品在473K下进行2小时的退火处理，以改善材料的结晶。TiO:Co/ITO/PET和TiO:Co/玻璃薄膜在可见光区域均表现出优异的光学性能，透过率超过80%。在样品合成过程中检测到ITO/PET表面温度升高；ITO基板上的这种变化（2K）与沉积过程中轰击的离子或原子的冲击能量有关。X射线衍射测量证明在柔性基板上有局部相生长；钴晶体在金红石相和锐钛矿相中的随机分布与嵌入磁性离子的晶格有关。通过扫描电子显微镜（SEM）和原子力显微镜（AFM）测量观察到薄膜表面存在小晶粒结构且没有团簇形成。从这项形貌研究和磁显微镜（MFM）测量证明，薄膜表面晶粒没有形成磁畴。通过物理性能测量系统（PPMS）测量的磁化强度随磁场变化的函数关系中观察到类似铁磁的行为。TiO:Co/ITO/PET薄膜在室温下的M-H曲线显示出磁滞回线。由于掺杂浓度低于12%，钴离子之间没有形成磁畴的偶极相互作用与材料中的磁行为相关。
