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Enhancement of the refrigerant capacity in low level boron doped La0.8Gd0.2Fe11.4Si1.6

Journal Article


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Abstract


  • The effects of boron doping on the itinerant-electron metamagnetic (IEM) transition and the magnetocaloric effects (MCEs) in the cubic NaZn13-type La0.8Gd0.2Fe11.4Si1.6 compound have been investigated. The Curie temperature, TC, of La0.8Gd0.2Fe11.4Si1.6Bx compounds with x=0, 0.03, 0.06, 0.2 and 0.3 was found to increase from 200 K to 222 K with increase in boron doping, x. The maximum values of the isothermal magnetic entropy change, ΔSM, (derived using the Maxwell relation for a field change ΔB=0–5 T) in La0.8Gd0.2Fe11.4Si1.6Bx with x=0, 0.03, 0.06, 0.2 and 0.3 are 14.8, 16, 15, 7.5 and 6.6 J kg−1 K−1 respectively, with corresponding values of the refrigerant capacity, RCP of 285, 361, 346, 222 and 245 J kg−1. The large ΔSM values observed for the undoped sample, and the low level B doped La0.8Gd0.2Fe11.4Si1.6B0.03 and La0.8Gd0.2Fe11.4Si1.6B0.06 compounds are attributed to the first order nature of the IEM transition while the decrease of ΔSM at x=0.2 and 0.3 is due to a change in the second order phase transition with increase in B doping. The nature of the magnetic phase transitions is also reflected by the magnetic hysteresis of 3.7, 9, 5.7, 0.4 and 0.3 J kg−1 for x=0.0, 0.03, 0.06, 0.2 and 0.30 respectively. The possibility of tuning the TC and the magnetocaloric properties at temperatures close to room temperature make this system interesting from the points of view of both fundamental aspects as well as applications.

Authors


  •   Shamba, Precious (external author)
  •   Zeng, R (external author)
  •   Wang, Jian Li.
  •   Campbell, Stewart J. (external author)
  •   Dou, Shi Xue

Publication Date


  • 2013

Citation


  • Shamba, P., Zeng, R., Wang, J. L., Campbell, S. J. & Dou, S. X. (2013). Enhancement of the refrigerant capacity in low level boron doped La0.8Gd0.2Fe11.4Si1.6. Journal of Magnetism and Magnetic Materials, 331 102-108.

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1297&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/292

Number Of Pages


  • 6

Start Page


  • 102

End Page


  • 108

Volume


  • 331

Abstract


  • The effects of boron doping on the itinerant-electron metamagnetic (IEM) transition and the magnetocaloric effects (MCEs) in the cubic NaZn13-type La0.8Gd0.2Fe11.4Si1.6 compound have been investigated. The Curie temperature, TC, of La0.8Gd0.2Fe11.4Si1.6Bx compounds with x=0, 0.03, 0.06, 0.2 and 0.3 was found to increase from 200 K to 222 K with increase in boron doping, x. The maximum values of the isothermal magnetic entropy change, ΔSM, (derived using the Maxwell relation for a field change ΔB=0–5 T) in La0.8Gd0.2Fe11.4Si1.6Bx with x=0, 0.03, 0.06, 0.2 and 0.3 are 14.8, 16, 15, 7.5 and 6.6 J kg−1 K−1 respectively, with corresponding values of the refrigerant capacity, RCP of 285, 361, 346, 222 and 245 J kg−1. The large ΔSM values observed for the undoped sample, and the low level B doped La0.8Gd0.2Fe11.4Si1.6B0.03 and La0.8Gd0.2Fe11.4Si1.6B0.06 compounds are attributed to the first order nature of the IEM transition while the decrease of ΔSM at x=0.2 and 0.3 is due to a change in the second order phase transition with increase in B doping. The nature of the magnetic phase transitions is also reflected by the magnetic hysteresis of 3.7, 9, 5.7, 0.4 and 0.3 J kg−1 for x=0.0, 0.03, 0.06, 0.2 and 0.30 respectively. The possibility of tuning the TC and the magnetocaloric properties at temperatures close to room temperature make this system interesting from the points of view of both fundamental aspects as well as applications.

Authors


  •   Shamba, Precious (external author)
  •   Zeng, R (external author)
  •   Wang, Jian Li.
  •   Campbell, Stewart J. (external author)
  •   Dou, Shi Xue

Publication Date


  • 2013

Citation


  • Shamba, P., Zeng, R., Wang, J. L., Campbell, S. J. & Dou, S. X. (2013). Enhancement of the refrigerant capacity in low level boron doped La0.8Gd0.2Fe11.4Si1.6. Journal of Magnetism and Magnetic Materials, 331 102-108.

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1297&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/292

Number Of Pages


  • 6

Start Page


  • 102

End Page


  • 108

Volume


  • 331