通过结构和磁性测量，对Ni4sCosMn37In18多晶样品的马氏体相变性质进行了系统研究，发现Co原子的间隙掺杂能够提高三元合金奥氏体相与马氏体相之间的磁化强度差异（AM）．以此为基础，结合基本热力学理论，总结了计算驱动完整马氏体相变所对应临界磁场在热力学上的一般表达式，并结合Ni45Co5Mn37In13的实验结果对该表达式进行了基本讨论，充分证明了磁场诱导马氏体相变不仅与该类合金两相之间的zg4有关，而且还依赖于合金在相变过程的温度跨度与热滞后．此外，计算了Ni4sCosMn37In15合金在磁场诱导马氏体相变过程中的反磁热效应．结果表明，该合金的饱和等温熵变约为27J／kgK．而且保持在一个非常宽的温度跨度内，以至于样品在50kOe磁场改变下的磁制冷量已经达到了约340J／kg．
The martensitic transformation properties in Ni45 Co5Mn37 In15 polycrystalline have been systematically investigated by means of structure and magnetic measurements. It is found that the magnetization difference (AM)between austenite and martensitic state is improved by appropriate Co doping. On the basis of above analysis and combing with thermodynamical mechanisms, we deduced a general equation of calculating the critical magnetic field, which can drive a complete martensitic transformation. According to this expression, the thermodynamical effect up- on field-induced martensitic transformation (FIMT) for Ni4sCo5 Mn37In13 alloy has been discussed. This sufficiently approved that the FIMT not only depends on △M between its both phases, but also relies on the span of temperature as well as thermal hysteresis during its martensitic transformation. Furthermore, we also calculated the magnetocaloric effect (MCE) upon FIMT in Ni4sCo5Mn37 In15 alloy. Such results show that the saturated isothermal entropy change in Ni15Co5Mn37 In13 is about 27 J/kg K and remains unchanged in a broad temperature interval, causing that the refrigeration capacity in this sample achieves to 340 J/kg.
参考文献
| [1] | O'Handley RC. .Model for strain and magnetization in magnetic shape-memory alloys[J].Journal of Applied Physics,1998(6):3263-3270. |
| [2] | Kainuma R;Imano Y;Ito W;Sutou Y;Morito H;Okamoto S;Kitakami O;Oikawa K;Fujita A;Kanomata T;Ishida K .Magnetic-field-induced shape recovery by reverse phase transformation.[J].Nature,2006(7079):957-960. |
| [3] | Krenke T;Duman E;Acet M;Wassermann EF;Moya X;Manosa L;Planes A .Inverse magnetocaloric effect in ferromagnetic Ni-Mn-Sn alloys[J].Nature materials,2005(6):450-454. |
| [4] | Jing, C;Li, Z;Zhang, HL;Chen, JP;Qiao, YF;Cao, SX;Zhang, JC .Martensitic transition and inverse magnetocaloric effect in Co doping Ni-Mn-Sn Heulser alloy[J].The European physical journal. B, Condensed Matter Physics,2009(2):193-196. |
| [5] | Vasil'ev AN.;Khovailo VV.;Dikshtein IE.;Shavrov VG. Buchelnikov VD.;Matsumoto M.;Suzuki S.;Takagi T.;Tani J.;Bozhko AD. .Structural and magnetic phase transitions in shape-memory alloys Ni2+xMn1-xGa[J].Physical Review.B.Condensed Matter,1999(2):1113-1120. |
| [6] | Pecharsky VK;Gschneidner KA .Giant magnetocaloric effect in Gd-5(Si2Ge2)[J].Physical review letters,1997(23):4494-4497. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%