CAJ | 학술논문

使用电弧熔炼法制备了La_(1.1) Fe_(11.4)Si_(1.55)Ge_(0.05)合金.研究了用少量的Ge替代Si后,La_(1.1) Fe_(11.4) Si_(1.55)Ge_(0.05)合金的磁性和磁热效应.粉末X射线衍射结果表明:在1273 K真空退火处理10 d后,合金La_(1.1) Fe_(11.4)Si_(1.55)Ge_(0.05)主相为NaZn_(13)型立方结构,存在微量的α-Fe相.热磁曲线M-T与Arrott曲线表明:在居里温度T_c=205 K处发生由铁磁性(T＜T_c)转变为顺磁性(T＞T_c)的二级磁相变.在磁场变化0-1.5 T下,根据等温磁化曲线通过Maxwell关系式计算得出最大磁熵变-△S_m~(max)=9 J·ks~(-1)·K~(-1).Ge替代Si后该合金在其居里温度T_c处-△S_m-T曲线半高宽增大,使合金的相对制冷能力RCP(S)有所提高.
사용전호용련법제비료La_(1.1) Fe_(11.4)Si_(1.55)Ge_(0.05)합금.연구료용소량적Ge체대Si후,La_(1.1) Fe_(11.4) Si_(1.55)Ge_(0.05)합금적자성화자열효응.분말X사선연사결과표명:재1273 K진공퇴화처리10 d후,합금La_(1.1) Fe_(11.4)Si_(1.55)Ge_(0.05)주상위NaZn_(13)형립방결구,존재미량적α-Fe상.열자곡선M-T여Arrott곡선표명:재거리온도T_c=205 K처발생유철자성(T＜T_c)전변위순자성(T＞T_c)적이급자상변.재자장변화0-1.5 T하,근거등온자화곡선통과Maxwell관계식계산득출최대자적변-△S_m~(max)=9 J·ks~(-1)·K~(-1).Ge체대Si후해합금재기거리온도T_c처-△S_m-T곡선반고관증대,사합금적상대제랭능력RCP(S)유소제고.
The La_(1.1)Fe_(11.4)Si_(1.55)Ge_(0.05) alloy was prepared by arc melting.The effect of MagnetocMoric Effect was investigated in La_(1.1) Fe_(11.4)Si_(1.55)Ge_(0.05) alloy by substituting small amount of Ge.The La_(1.1)Fe_(11.4)GexSi_(1.6-x) alloy was prepared by annealing in all evacuated quartz tube for 10 d at 1273 K.XRD analysis showed that the alloy could be stabilized with Ge substitution in the NaZn_(13)-type structure and minor amount of α-Fe phase.The curves of M-T and Arrott indicated that the metamagnetic transformation was a second-phase between ferromagnetism and paramagnetism.On the magnetic field change of 0-1.5 T.Maxwell relation was employed to calculate the maximum magnetic entropy change of -△S_m~(max)=9 J·kg~(-1)·K~(-1).The Curie temperature of La_(1.1) Fe_(11.4) Si_(1.55) Ge_(0.05) alloy was increased. Both the full width at half maximum of isothermal magnetic entropy change-△S_m~(max),and the relative cooling power RCP(s)of La_(1.1)Fe_(11.4) Si_(1.55)Ge_(0.05) alloy increased.