Sm＿2（Fe，M）＿（17）C＿（1．5）（M＝Ga，Si）化合物的形成和磁性

FORMATION AND MAGNETIC PROPERTIES OF Sm_2Fe_(17-x)M_xC_(1.5)(M=Ga,Si)COMPOUNDS S_(HEN)

用电弧炉熔炼方法制备了Ｓｍ＿２Ｆｅ＿（１７－ｓ）Ｍ＿ｘＣ＿（１．５）（Ｍ＝Ｇａ，Ｓｉ）化合物，研究了它们的形成、结构与磁性。实验结果表明，用Ｇａ替代Ｆｅ，当２≤ｘ≤６时，可形成Ｔｈ＿２Ｚｎ＿（１７）型单相化合物，而Ｓｉ的替代仅在ｘ＝２时为单相结构。居里温度随Ｇａ含量的增加从ｘ＝２时的６３３Ｋ下降到ｘ＝６时的３５１Ｋ，Ｓｍ＿２Ｆｅ＿（１５）Ｓｉ＿２Ｃ＿（１．５）的Ｔｃ为５７８Ｋ。Ｓｍ＿２Ｆｅ＿（１４）Ｇａ＿３Ｃ＿（１．５）和Ｓｍ＿２Ｆｅ＿（１５）Ｓｉ＿２Ｃ＿（１．５）化合物的室温各向异性场分别为９０和１１５ｋＯｅ。用快淬方法获得Ｓｍ＿２Ｆｅ＿（１５）Ｇａ＿２Ｃ＿（１．５）的室温矫顽力Ｈｃ＝１６ｋＯｅ。

Formation,structure and magnetic properties of Sm_2Fe_(17-x)M_xC_(1.5)(M=Ga,Si)co-mpounds prepared by arc-melting were studied. The Sm_2Fe_(17-x)Ga_xC_(1.5)(3≤x≤6) ca-rbides crystallize in the rhombohedral Th_2Zn_(17-type) structure and the single-phase co-mpund of Sm_2Fe_(17-x)Si_xC_(1.5) can only be obtained as x is 2. It is found that the Curietemperature of Sm_2Fe_(17-x)Ga_xC_(1.5) compounds decreases monotonically with increasingGa concentration x from 633K for x=2 to 351K for x=6, and the Tc of Sm_2Fe_(15)Si_2C_(1.5)compound is 578K. All compounds studied in this work exhibit an easy c-axis anisotropy at room temperature.The anisotropy field of Sm_2Fe_(14)Ga_3C_(1.5)and Sm_2Fe_(15)Si_2C_(1.5)compounds is found to be 90 and 115 kOe, respectively.A room-tempera-ture coercivity of 16 kOe is obtained in rapidly quenched Sm_2Fe_(15)Ga_2C_(1.5) alloy prepa-red at a speed of 25 m/s.