Effective surface area of SnO2 sputtered films evaluated by measurement of physical adsorption isotherms Toshinari Yamazaki, Tomoyasu Furuta, Yanbai Shen, Chengji Jin, Toshio Kikuta, Noriyuki Nakatani Jpn. J. Appl. Phys., 45(12), 9180-9184 (2006). Dec.