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The correlation of microstructure and magnetic properties in Sm(CobalFe0.1Cu0.1Zr0.033)6.93 magnets solution-treated at different temperatures was systematically investigated.It is found that the magnets solution-treated at 1219 ℃ possess a single 1∶7H phase,exhibiting the homogeneous cellular structure during further aging treatment,leading to the optimum magnetic properties.However,for the magnets solution-treated at 1211 and 1223 ℃,2∶17H or 1∶5H secondary phase will also form besides 1∶7H main phase,which cannot transform into cellular structure,thus deteriorating the magnetic properties greatly.The irreversible magnetization investigations with recoil loops also propose a non-uniform pinning in the magnets induced by the secondary precipitates.At proper solution temperature,Zr is supposed to occupy the Fe-Fe dumbbell sites in the form of Zr-vacancy pairs,leading to the minimum c/a ratio and thus stabilizing the l∶7H phase.Finally,Sm(CobalFe0.1Cu0.1Zr0.033)6.93 magnets with the maximum energy product and intrinsic coercivity at 550 ℃ up to 60.73 kJ·m-3 and 553.88 kA·m-1 were prepared by powder metallurgy method.