Effects of the Fe3+/Sr2+ molar ratio on the exchange-coupling of the composite and single-phase SrFe12O19Yuanfeng Xu, Yongqing Ma, Xian Zhang, Ganhong Zheng, Zhenxiang Dai, Qian Ma, Fenlian Zan, Guang Li and Mingzai WuEur. Phys. J. Appl. Phys., 62 1 (2013) 10201DOI: https://doi.org/10.1051/epjap/2013120267