Magnetic relaxation and collective vortex creep in FeTe0.6Se0.4 single crystal Yue Sun, Toshihiro Taen, Yuji Tsuchiya, Sunseng Pyon, Zhixiang Shi and Tsuyoshi Tamegai EPL, 103 5 (2013) 57013 Published online: 30 September 2013 DOI: 10.1209/0295-5075/103/57013