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Full-Text Articles in Social and Behavioral Sciences

The Magnetocaloric Effect And Critical Behaviour Of The Mn0.94ti0.06coge Alloy, P Shamba, Jianli Wang, J C. Debnath, S J. Kennedy, Rong Zeng, M F Md Din, F Hong, Z X. Cheng, A J. Studer, S X. Dou Jun 2013

The Magnetocaloric Effect And Critical Behaviour Of The Mn0.94ti0.06coge Alloy, P Shamba, Jianli Wang, J C. Debnath, S J. Kennedy, Rong Zeng, M F Md Din, F Hong, Z X. Cheng, A J. Studer, S X. Dou

Shi Xue Dou

Structural, magnetic and magnetocaloric properties of the Mn0.94Ti0.06CoGe alloy have been investigated using x-ray diffraction, DC magnetization and neutron diffraction measurements. Two phase transitions have been detected, at T-str = 235 K and T-C = 270 K. A giant magnetocaloric effect has been obtained at around Tstr associated with a structural phase transition from the low temperature orthorhombic TiNiSi-type structure to the high temperature hexagonal Ni2In-type structure, which is confirmed by neutron study. In the vicinity of the structural transition, at T-str, the magnetic entropy change, -Delta S-M reached a maximum value of 14.8 J kg(-1) K-1 under a magnetic …


Graphene Micro-Substrate Induced High Electron-Phonon Coupling In Mgb2, W X. Li, X Xu, K S. B De Silva, F X. Xiang, S X. Dou Jun 2013

Graphene Micro-Substrate Induced High Electron-Phonon Coupling In Mgb2, W X. Li, X Xu, K S. B De Silva, F X. Xiang, S X. Dou

Shi Xue Dou

Electron-phonon coupling strength was studied in graphene-MgB2 composites to explore the possibilities for a higher superconducting transition temperature (Tc). For the first time in the experimental work on MgB2, the Raman active E2g mode was split into two parts: a softened mode corresponding to tensile strain and a hardened mode attributed to the carbon substitution effect. The tensile strain effect is suggested to improve Tc of graphene-MgB2 composites because it increases the electron-phonon coupling strength of MgB2.


Effect Of Gallium Doping And Ball Milling Process On The Thermoelectric Performance Of N-Type Zno, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou Jun 2013

Effect Of Gallium Doping And Ball Milling Process On The Thermoelectric Performance Of N-Type Zno, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou

Shi Xue Dou

We report a systematic investigation of the thermoelectric properties of n-type Ga-doped ZnO synthesized using different ball milling conditions. Samples fabricated by the high-energy ball milling resulted in a highly dense layered structure with randomly distributed voids. These samples measured the lowest room temperature thermal conductivity, i.e., 27 W/mK due to increased phonon scattering. Furthermore, the Ga:ZnO system showed a metal–semiconductor transition above 300 K with transition temperature decreasing with increasing doping level. Measurement of the activation energy revealed the presence of one donor level around 3.9–7.8 meV and a deeper donor level around 15.4–18.1 meV below the conduction band …


Enhancement Of The Refrigerant Capacity In Low Level Boron Doped La0.8gd0.2fe11.4si1.6, P Shamba, R Zeng, Jianli Wang, S J. Campbell, S X. Dou Jun 2013

Enhancement Of The Refrigerant Capacity In Low Level Boron Doped La0.8gd0.2fe11.4si1.6, P Shamba, R Zeng, Jianli Wang, S J. Campbell, S X. Dou

Shi Xue Dou

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 …