(Color online) (a) Room-temperature x-ray powder diffractions for all the samples ZnC x Fe3 (1.0 ≤ x ≤ 1.5); (b) The refined lattice constant a as a function of the carbon concentration x. (c) The Rietveld refined powder XRD patterns for ZnC1.2Fe3; the vertical marks (blue line) indicate the position of Bragg peaks, and the solid line (green line) at the bottom corresponding to the difference between observed and calculated intensities.
(Color online) Temperature dependent magnetization M(T) curves are measured at 100 Oe under ZFC/FCC/FCW processes for ZnC x Fe3(1.2 ≤ x ≤ 1.5): (a) x = 1.2; (b) x = 1.3; (c) x = 1.4; (d) x = 1.5; (e) Isotherm magnetization M(H) curves of ZnC x Fe3(1.2 ≤ x ≤ 1.5) at 5 K with field up to 45 kOe; inset shows the enlargements of M(H) curves under positive higher magnetic fields; (f) x-dependent values of T C and M S for x = 1.2, 1.3, 1.4, and 1.5.
(Color online) Temperature dependent M(T)ZFC curves and resistivity ρ(T) at zero field for ZnC x Fe3(1.2 ≤ x ≤ 1.5): (a) x = 1.2; (b) x = 1.3; (c) x = 1.4; (d) x = 1.5.
(Color online) (a) Temperature dependent resistivity ρ(T) at zero field for ZnC x Fe3 (x ≥ 1.2); Left inset: lower-T ρ(T) data plotted as ρ(T) vs T 2; right inset: linear fits of ρ(T) data for all the samples ZnC x Fe3 (x ≥ 1.2) between 70 and 200 K; Solid lines are fitting results for both cases. (b) x-dependent values of the residual resistivity ρ0 and the fitting coefficient A for ZnC x Fe3 (1.2 ≤ x ≤ 1.5).
(Color online) Temperature dependent heat capacity C P (T) at zero field for ZnC1.2Fe3. Inset shows the plot of C P (T)/T vs T 2 below 20 K and the solid line represents the fitting results according to Eq. (1).
(Color online) (a) Isotherm magnetization M(H) curves for ZnC1.2Fe3 covering a broad temperature range of 250–394 K with external magnetic fields up to 45 kOe; (b) Arrott plots deduced from M(H) curves in Fig. 6(a) with the temperature range of 340–370 K.
(Color online) (a) Magnetic entropy change −ΔS M as a function of temperature (250–394 K) under different magnetic field changes of ΔH = 5, 10, 20, 30, 40, and 45 kOe for ZnC1.2Fe3. Inset shows the plot of the maximum magnetic entropy change vs H 2/3 for ZnC1.2Fe3. The red line indicates the linear fitting results. (b) The −ΔS M -T curve for magnetic field change ΔH = 45 kOe. The closed area represents the relative cooling powder (RCP). Inset shows H-dependent RCP. (c) A comparison of RCP of ZnC1.2Fe3 (ΔH = 45 kOe) with those of potential candidates for magnetic refrigerator such as Gd, Gd5Si2Ge2, CdCrS2, TbCoAl (ΔH = 50 kOe), La0.67Ca0.33MnO3 (ΔH = 30 kOe) and isostructural GaCMn3, AlCMn3 (ΔH = 45 kOe). The dash line is guide to the eye.
(Color online) (a) Temperature dependent thermal conductivity κ(T), electronic thermal conductivity κ e , lattice thermal conductivity κ L for ZnC1.2Fe3 at zero field (5–350 K); (b) Temperature dependent Seebeck coefficient α(T) at zero field. (c) The dimensionless figure of merit (ZT = α2T/ρk) is plotted as a function of temperature at zero field. (d) A comparison of ZT of ZnC1.2Fe3 with other typical thermoelectric materials such as Co0.3Ti0.7S2, LaGdS3, La0.04Sr0.96TiO3, TiS2, (In2Te3)0.08(SnTe)0.92, SmGdS3, CuSbSe2, and La0.875Sr0.125CoO3. The dash line is guide to the eye.
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