The effects of non-magnetic atom vacancy on structural, martensitic phase transitions and the corresponding magnetocMoric effect in MnCoGel-x alloys are investigated using x-ray diffraction and magnetic measurements. ...The effects of non-magnetic atom vacancy on structural, martensitic phase transitions and the corresponding magnetocMoric effect in MnCoGel-x alloys are investigated using x-ray diffraction and magnetic measurements. The introduction of non-magnetic atom vacancy leads to the decrease of the martensitic transition temperature and realizes a temperature window where magnetic and martensitic phase transitions can be tuned together. Moreover, the giant magnetocaloric effect accompanied with the coupled magnetic-structural transition is ob- tained. It is observed that the peak values of magnetic entropy change of MnCoGeo.97 are about -13.9, -35.1 and -47.4J.kg-1K-1 for △H = 2, 5, 7T, respectively.展开更多
To evaluate the possibility of using Gd-Si-Ge alloys in magnetic refrigerators, samples of Gd-Si-Ge alloys were made of domestic Gd. The magnetocaloric effect of samples was estimated by magnetic entropy change (-ΔS_...To evaluate the possibility of using Gd-Si-Ge alloys in magnetic refrigerators, samples of Gd-Si-Ge alloys were made of domestic Gd. The magnetocaloric effect of samples was estimated by magnetic entropy change (-ΔS_m) calculated from M-H curves according to Maxwell relation. The first order phase transformation was destroyed due to the impurities in the commercial Gd, so that no giant magnetocaloric effect was found. The samples made of purified Gd exhibit first order phase transformation, and the -ΔS_m is basically consistent with the published data of Ames laboratory, USA. This work proves that Gd-Si-Ge alloys made of domestic Gd can be utilized in magnetic refrigerators.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11504222
文摘The effects of non-magnetic atom vacancy on structural, martensitic phase transitions and the corresponding magnetocMoric effect in MnCoGel-x alloys are investigated using x-ray diffraction and magnetic measurements. The introduction of non-magnetic atom vacancy leads to the decrease of the martensitic transition temperature and realizes a temperature window where magnetic and martensitic phase transitions can be tuned together. Moreover, the giant magnetocaloric effect accompanied with the coupled magnetic-structural transition is ob- tained. It is observed that the peak values of magnetic entropy change of MnCoGeo.97 are about -13.9, -35.1 and -47.4J.kg-1K-1 for △H = 2, 5, 7T, respectively.
文摘To evaluate the possibility of using Gd-Si-Ge alloys in magnetic refrigerators, samples of Gd-Si-Ge alloys were made of domestic Gd. The magnetocaloric effect of samples was estimated by magnetic entropy change (-ΔS_m) calculated from M-H curves according to Maxwell relation. The first order phase transformation was destroyed due to the impurities in the commercial Gd, so that no giant magnetocaloric effect was found. The samples made of purified Gd exhibit first order phase transformation, and the -ΔS_m is basically consistent with the published data of Ames laboratory, USA. This work proves that Gd-Si-Ge alloys made of domestic Gd can be utilized in magnetic refrigerators.
