Isothermal Magnetic Entropy Change Research Articles

Magnetocaloric properties of Eu1−xLaxTiO3 (0.01 ≤ x ≤ 0.2) for cryogenic magnetic cooling

We report magnetic and magnetocaloric (MCE) properties of polycrystalline Eu1−xLaxTiO3 samples over a wide composition range (0.01 ≤ x ≤ 0.20). It is found that the ground state changes from antiferromagnetic for x = 0.01 (TN = 5.2 K) to ferromagnetic for x ≥ 0.03 and the ferromagnetic Curie temperature increases from TC = 5.7 K for x = 0.03 to TC = 7.9 K for x = 0.20. The x = 0.01 sample shows a large reversible isothermal magnetic entropy change of −ΔSm = 23 (41.5) J/kg K and adiabatic temperature change of ΔTad = 9 (17.2) K around 6.7 K for a field change of μ0ΔH = 2 (5) Tesla. Although the peak value of −ΔSm decreases as La content increases, it is impressive in x = 0.2(−ΔSm = 31.41 J/kg K at T = 7.5 K for μ0ΔH = 5 T). The large value of MCE arises from suppression of the spin entropy associated with the localized moment (J = 7/2) of Eu2+:4f7 ions. This large MCE over a wide compositional range suggests that the Eu1−xLaxTiO3 series could be useful for magnetic cooling below 40 K.

Magnetic ordering of YPd2Si-type HoNi2Si and ErNi2Si compounds

Magnetic properties of YPd2Si-type HoNi2Si and ErNi2Si were investigated via neutron diffraction and magnetisation measurements. HoNi2Si and ErNi2Si show ferromagnetic-like ordering at TC of 9K and 7K, respectively. The paramagnetic Weiss temperatures are 9K and 11K and the effective magnetic moments are 10.76μB/fu and 9.79μB/fu for HoNi2Si and ErNi2Si compounds, respectively. The HoNi2Si and ErNi2Si are soft ferromagnets with saturation magnetization of 8.1μB/fu and 7.5μB/fu, respectively at 2K and in field of 140kOe. The isothermal magnetic entropy change, ΔSm, has a maximum value of −15.6J/kg·K at 10K for HoNi2Si and −13.9J/kg·K at 6K for ErNi2Si for a field change of 50kOe.Neutron diffraction study in zero applied field shows mixed ferromagnetic-antiferromagnetic ordering of HoNi2Si at ~9K and its magnetic structure is a sum of a-axis ferromagnetic Fa, b-axis antiferromagnetic AFb and c-axis antiferrromagnetic AFc components of Pn′a21′={1, mx′/[1/2, 1/2, 1/2], 2y′/[0, 1/2, 0], mz/[1/2, 0, 1/2]} magnetic space group and propagation vector K0=[0, 0, 0]. The holmium magnetic moment reaches a value of 9.23(9)μB at 1.5K and the unit cell of HoNi2Si undergoes isotropic contraction around the temperature of magnetic transition.

Giant magnetic coercivity in YNi4B-type SmNi3TB (T=Mn–Cu) solid solutions

The effects of transition metal substitution for Ni on the magnetic properties of the YNi4B-type SmNi4B via SmNi3TB (T=Mn, Fe, Co, Cu) solid solutions have been investigated. SmNi4B, SmNi3MnB, SmNi3FeB, SmNi3CoB and SmNi3CuB show ferromagnetic ordering at 40K, 210K, 322K, 90K and 57K and field sensitive metamagnetic-like transitions at 15K, 100K, 185K, 55K and 15K in a magnetic field of 10kOe, respectively. The magnetocaloric effects of SmNi3TB (T=Mn–Cu) were calculated in terms of isothermal magnetic entropy change (ΔSm). The magnetic entropy ΔSm reaches value of –0.94J/kgK at 40K for SmNi4B, –1.5J/kgK at 205K for SmNi3MnB, –0.54J/kgK at 320K for SmNi3FeB, –0.49J/kgK at 90K for SmNi3CoB and –0.54J/kgK at 60K for SmNi3CuB in field change of 0–50kOe around the Curie temperature. They show positive ΔSm of +0.71J/kgK at ~10K for SmNi4B, +1.69J/kgK at 30K for SmNi3MnB, +0.89J/kgK at 110K for SmNi3FeB, +1.08J/kgK at 25K for SmNi3CoB and +1.12J/kgK at 10K for SmNi3CuB in field change of 0–50kOe around the low temperature metamagnetic-like transition. Below the field induced transition temperature (change of magnetic structure), SmNi3TB (T=Mn–Cu) exhibits giant magnetic coercivity of 74kOe at 5K for SmNi4B, 69kOe at 20K (90kOe at 10K) for SmNi3MnB, 77kOe at 60K for SmNi3FeB, 88kOe at 20K for SmNi3CoB and 52kOe at 5K for SmNi3CuB.

Electronic and magnetic properties of TbNi4Si: Ab initio calculations, mean field approximation and Monte Carlo simulation

Using the density functional theory, the electronic structure; density of states, band structure and exchange couplings of TbNi4Si compound have been investigated. Magnetic and magnetocaloric properties of this material have been studied using Monte Carlo Simulation (MCS) and Mean Field Approximation (MFA) within a three dimensional Ising model. We calculated the isothermal magnetic entropy change, adiabatic temperature change and relative cooling power (RCP) for different external magnetic field and temperature. The highest obtained isothermal magnetic entropy change is of −14.52Jkg−1K−1 for a magnetic field of H=4T. The adiabatic temperature reaches a maximum value equal to 3.7K and the RCP maximum value is found to be 125.12Jkg−1 for a field magnetic of 14T.

Magnetic ordering in Sc2CoSi2-type R2FeSi2 (R=Gd, Tb) and R2CoSi2 (R=Y, Gd–Er) compounds

Magnetic and magnetocaloric properties of Sc2CoSi2-type R2TSi2 (R=Gd–Er, T=Fe, Co) compounds have been studied using magnetization data. These indicate the presence of mixed ferromagnetic and antiferromagnetic interactions in these compounds. One observes a ferromagnetic transition followed by an antiferromagnetic order and a further possible spin-reorientation transition at low temperatures. Compared to Gd2{Fe, Co}Si2, the Tb2FeSi2 and {Tb–Er}2CoSi2 compounds exhibit remarkable hysteresis (for e.g. Tb2FeSi2 shows residual magnetization Mres/Tb=2.45μB, coercive field Hcoer=14.9kOe, and critical field Hcrit~5kOe at 5K) possibly due to the magnetocrystalline anisotropy of the rare earth. The R2{Fe, Co}Si2 show relatively small magnetocaloric effect (i.e. isothermal magnetic entropy change, ΔSm) around the magnetic transition temperature: the maximal value of MCE is demonstrated by Ho2CoSi2 (ΔSm=−8.1J/kgK at 72K and ΔSm=−9.4J/kgK at 23K in field change of 50kOe) and Er2CoSi2 (ΔSm=−13.6J/kgK at 32K and ΔSm=−8.4J/kgK at 12K in field change of 50kOe).

Study of magnetic entropy and heat capacity in ferrimagnetic Fe3Se4 nanorods

Change in the magnetic entropy and specific heat capacity in Fe3Se4 nanorods synthesized by a wet-chemical method in a broad temperature (215–340 K) and magnetic field range (0–60 k Oe) was studied. The isothermal magnetic entropy change (ΔSM) is estimated by an indirect method from the isothermal magnetization curves measured in this temperature range. of −46 × 10−2 J kg−1 · K−1 was obtained at ~317 K when the field was changed from 0 to 60 kOe. The maximum in the isothermal magnetic entropy change (ΔSM) is observed in close proximity to TC (~323 K), which is linked to the order–disorder transition. The nature of this transition was analyzed by universal curve behavior. The temperature and magnetic field dependence of specific heat capacity was studied and analyzed to estimate the adiabatic temperature change (ΔTad). The magnetic entropy change of Fe3Se4 nanoparticles is found to be comparable with similar ferrite and manganite nanoparticle systems and a broad operating temperature window of ~30 K was observed around room temperature.

Large adiabatic temperature and magnetic entropy changes inEuTiO3

We have investigated the magnetocaloric effect in single and polycrystalline samples of quantum paraelectric EuTiO3 by magnetization and heat capacity measurements. Single crystalline EuTiO3 shows antiferromagnetic ordering due to Eu2+ magnetic moments below TN = 5.6 K. This compound shows a giant magnetocaloric effect around its Neel temperature. The isothermal magnetic entropy change is 49 Jkg-1K-1, the adiabatic temperature change is 21 K and the refrigeration capacity is 500 JKg-1 for a field change of 7 T at TN. The single crystal and polycrystalline samples show similar values of the magnetic entropy change and adiabatic temperature changes. The large magnetocaloric effect is due to suppression of the spin entropy associated with localized 4f moment of Eu2+ ions. The giant magnetocaloric effect together with negligible hysteresis, suggest that EuTiO3 could be a potential material for magnetic refrigeration below 20 K.

Enhanced Refrigerant Capacity and Magnetic Entropy Nearly Flattening in (La 2 / 3 Ba 1 / 3 MnO 3 ) 1 − x / (La 2 / 3 Ba 1 / 3 MnO 2 . 9 8 ) x Composite

We report the enhancement of the refrigerant capacity (RC) and the working temperature span (δTFWHM) in (La2/3Ba1/3MnO3)1−x/ (La2/3 Ba1/3 MnO2.98)x composite. La2/3Ba1/3MnO3 and La2/3 Ba1/3MnO2.98 manganites are characterized, respectively, by Curie temperatures TC = 336.8 and 310 K near room temperature. The temperature dependence of the isothermal magnetic entropy change ΔS(T) has been calculated for the composite system with 0 ≤ x ≤ 1. We have shown that the full-width at half maximum of the ΔS(T) curve in La2/3Ba1/3MnO3 manganite may be significantly increased via a composite made of both samples with different values of TC. The optimum MCE at µ0H = 1 T has been found in the temperature interval of 299–349 K for the composite with x = 0.5. Even though the maximum value of ΔS for the composite is lower than those of the individual materials, the existence of a flattening behavior maximizes the refrigerant capacity, reaching values around 76.83 J/kg for an applied magnetic field change of 1 T. An optimal molar composite was simulated to be considered as a refrigerant material in a magnetic refrigerator performing an Ericsson cycle near room temperature. These results make the (La2/3Ba1/3MnO3)0.5/(La2/3Ba1/3MnO2.98)0.5 composite promising materials for the practical magnetic refrigeration using a lower field (1 T) which is much easier to generate by permanent magnets than higher fields like 2 T.

Metamagnetism-enhanced magnetocaloric effect in the rare earth intermetallic compound Ho5Ge4

Magnetic and magnetocaloric properties of polycrystalline Ho5Ge4 (orthorhombic, Sm5Ge4-type, Space group Pnma, No. 62, oP36) compound have been studied. This compound orders antiferromagnetically at ~24K (TN). From the magnetization vs field isotherms obtained close to the magnetic transition temperature, magnetocaloric effect (MCE) has been estimated. The isothermal magnetic entropy change (ΔSM) reaches a maximum value of ~−27J/kg-K at ~30K for a field change of 140kOe. A metamagnetic transition is observed in the field dependent magnetization data at temperatures below 20K, for critical fields above 20kOe, giving rise to a ferromagnetic order and hence a large MCE. The magnetic moment value at 2.5K is ~8μB/Ho3+ in 90kOe field.

Effect of microstructure and texture on the magnetic and magnetocaloric properties of the melt-spun rare earth intermetallic compound DyNi

Magnetization measurements have been carried out on the melt-spun ribbon sample of the rare earth intermetallic compound DyNi (Orthorhombic, FeB-type, Space group Pnma) and its magnetic and magnetocaloric properties are compared with those of the arc-melted analog. The arc-melted DyNi orders ferromagnetically at around 61K (TC) whereas the melt-spun DyNi orders ferromagnetically at about 47K. The maximum isothermal magnetic entropy change, ∆Smmax, near TC of the arc-melted and the melt-spun DyNi is found to be −32.7J/kgK and −22.4J/kgK, respectively, for a field change of 140kOe. For low magnetic field changes of ~20kOe, the relative cooling power (RCP) is ~660J/kg for the arc melted DyNi and ~460J/kg for the melt-spun ribbon. The reduction in TC and magnetocaloric effect may be attributed to the microstructure-induced anisotropy developed during the melt-spinning process.

Nanoscale {LnIII(24)ZnII(6)} Triangular Metalloring with Magnetic Refrigerant, Slow Magnetic Relaxation, and Fluorescent Properties.

The self-assembly of Ln(ClO4)3 · 6H2O and Zn(OAc)2 · 2H2O with pyrazine-2-carboxylic acid (HL) results in the formation of three novel nanosized {LnIII(24)ZnII(6)} triangular metallorings, [Gd24Zn6L24(OAc)22(μ3-OH)30(H2O)14](ClO4)7(OAc) · 2CH3OH · 26H2O (1), [Tb24Zn6L24(OAc)22(μ3-OH)30(CH3O)2(CH3OH)2(H2O)10](ClO4)5(OH) · 6CH3OH · 12H2O (2), and (H3O)[Dy24Zn6L24(OAc)22(μ3-OH)30(H2O)14](ClO4)7(OAc)2 · 4CH3OH · 22H2O (3), having the largest nuclearity among any known Ln/Zn clusters. Magnetic and luminescent studies reveal the special prowess for each lanthanide complex. Magnetic studies reveal that 1 exhibits a significant cryogenic magnetocaloric effect with a maximum -ΔSm (isothermal magnetic entropy change) value of 30.0 J kg(-1) K(-1) at 2.5 K and 7 T and that a slow magnetization relaxation is observed for the dysprosium analogue. In addition, the solid-state photophysical properties of 2 display strong characteristic Tb(III) photoluminescent emission in the visible region, suggesting that Tb(III)-based luminescence is sensitized by the effective energy transfer from the ligand HL to the metal centers.

RNi8Si3 (R=Gd,Tb): Novel ternary ordered derivatives of the BaCd11 type

The title compounds have been synthesized and characterized both from the structural and magnetic point of view. Both crystallize in a new monoclinic structure strictly related to the tetragonal BaCd11 type. The structure was solved by means of X-ray single-crystal techniques for GdNi8Si3 and confirmed for TbNi8Si3 on powder data; the corresponding lattice parameters (obtained from Guinier powder patterns) are a=6.3259(2), b=13.7245(5), c=7.4949(3)Å, β=113.522(3)°, Vcell=596.64(3)Å3 and a=6.3200(2), b=13.6987(4), c=7.4923(2)Å, β=113.494(2)°, Vcell=594.88(2)Å3. The symmetry relationship between the tI48-I41/amd BaCd11 aristotype and the new ordered mS48-C2/c GdNi8Si3 derivative is described via the Bärnighausen formalism within the group theory.The large Gd–Gd (Tb–Tb) distances, mediated via Ni–Si network, likely lead to weak magnetic interactions. Low-field magnetization vs temperature measurements indicate weak and field-sensitive antiferromagnetic ground state, with ordering temperatures of 3K in GdNi8Si3 and about 2–3K in TbNi8Si3. On the other hand, the isothermal field-dependent magnetization data show the presence of competing interactions in both compounds, with a field-induced ferromagnetic behavior for GdNi8Si3 and a ferrimagnetic-like behavior in TbNi8Si3 at the ordering temperature TC/N of about (or slightly higher than) 3K. The magnetocaloric effect, quantified in terms of isothermal magnetic entropy change ΔSm, has the maximum values of –19.8J(kgK)−1 (at 4K for 140kOe field change) and −12.1J(kgK)−1 (at 12K for 140kOe field change) in GdNi8Si3 and TbNi8Si3, respectively.

Enhancement of Refrigeration Capacity and Table-Like Magnetocaloric Effect in LaFe 10.7Co 0.8Si 1.5/ La 0.6Pr 0.4Fe 10.7Co 0.8Si 1.5 Composite

In this work, we have investigated the magnetocaloric effect (MCE) in a two-phase composite system (LaFeCoSi) 1−x/(LaPrFeCoSi) x based on LaFe 10.7 Co 0.8Si 1.5 and La 0.6Pr 0.4Fe 10.7Co 0.8Si 1.5 with Curie temperature values 275 and 295 K, respectively. The temperature dependence of the isothermal magnetic entropy change, ΔS(T), has been calculated for the biphasic system with 0<x<1. The optimum MCE properties, i.e., a ΔS(T) curve with table-like shape, has been found in the temperature interval of 271–287 K for the composite with x = 0.45 at 5 T. The |ΔSM| of the composite come close to a constant value of 9.78 J/(kg K) in a field change of 0–5 T in a wide temperature span over 16 K resulting in large refrigerant capacity value of ∼534.45 J/kg. This composite can be used as the working material in the Ericsson cycle magnetic regenerative refrigerator. Our findings constitute a good starting point to stimulate the search for new composites with enhanced MCE properties near room temperature.

Giant magnetic coercivity in CaCu5-type SmNi3TSi (T=Mn–Cu) solid solutions

The effects of transition metal substitution for Ni on the magnetic properties of the CaCu5-type SmNi3TSi (T=Mn, Fe, Co, Cu) solid solutions have been investigated. SmNi3MnSi, SmNi3FeSi, SmNi3CoSi and SmNi3CuSi show ferromagnetic ordering at 125K, 190K, 46K and 12K and field induced transitions at 65K, 110K, 30K and 6K, respectively. The magnetocaloric effects of SmNi3TSi (T=Mn, Fe, Co, Cu) were calculated in terms of isothermal magnetic entropy change (ΔSm). The magnetic entropy ΔSm reaches value of −1.1J/kgK at 130K for SmNi3MnSi, −0.4J/kgK at 180K for SmNi3FeSi, −0.37J/kgK at 45K for SmNi3CoSi and −0.5J/kgK at 12K for SmNi3CuSi in field change of 0–50kOe around the ferromagnetic ordering temperature. They show positive ΔSm of +2.4J/kgK at 30K for SmNi3MnSi, −2.6J/kgK at 65K for SmNi3FeSi, +0.73J/kgK at 15K for SmNi3CoSi and −0.5J/kgK at 6K for SmNi3CuSi in field change of 0–50kOe around the metamagnetic-like transition temperature. Below the field induced transition temperature, SmNi3TSi (T=Mn, Fe, Co, Cu) exhibits giant magnetic coercivity of 80kOe at 20K for SmNi3MnSi, 87kOe at 40K for SmNi3FeSi, 27kOe at 20K for SmNi3CoSi and 54kOe at 5K for SmNi3CuSi.

Magnetic order of Y3NiSi3-type R3NiSi3 (R=Gd–DY) compounds

Magnetic measurements and neutron powder diffraction investigations on the Y3NiSi3-type R3NiSi3 compounds (R=Gd, Tb, Dy) reveal their complex antiferromagnetic ordering. Magnetic measurements on Gd3NiSi3, Tb3NiSi3 and Dy3NiSi3 indicate antiferromagnetic-like transition at temperatures 260K, 202K and 140K, respectively. Also, the Tb3NiSi3 and Dy3NiSi3 compounds show spin-reorientation transition at 132K and 99K, respectively. Below the spin-reorientation transition, the isothermal magnetization curves indicate the metamagnetic-like behavior of Tb3NiSi3 and Dy3NiSi3. The magnetocaloric effect of Dy3NiSi3 is calculated in terms of isothermal magnetic entropy change and it reaches a maximum value of −1.2J/kgK and −1.1J/kgK for a field change of 50kOe near 146K and 92K, respectively. The neutron diffraction studies of Tb3NiSi3 suggest the magnetic ordering of the Tb2 4j sublattice and no magnetic ordering of the Tb1 2a sublattice. Tb3NiSi3 transforms from the high temperature paramagnetic state to the commensurate high-temperature a- and c-axis antiferromagnet of I′2/m magnetic space group below 250K. Below 150K, the high-temperature antiferromagnet transforms into the low-temperature a-, b- and c-axis antiferromagnet of I′i magnetic space group. At 1.5K, the terbium magnetic moment in Tb2 sublattice and its a-, b- and c-axis components reach the values of MTb2=8.2(1) μB, MaTb2=5.9(1) μB, MbTb2=4.3(2) μB and McTb2=3.7(2) μB, respectively.

Magnetocaloric effect in (La1−xSmx)0.67Pb0.33MnO3 (0 ≤ x ≤ 0.3) manganites near room temperature

We present an investigation on structure, magnetic and magnetocaloric properties of the perovskite manganites (La1−xSmx)0.67Pb0.33MnO3 (x = 0, 0.1, 0.2, 0.3) synthesized by sol–gel technique. The XRD patterns show that all synthesized samples have reflections typical of the perovskite structure with orthorhombic symmetry. Thermomagnetic measurements showed that all the samples display a paramagnetic–ferromagnetic transition with decreasing temperature. The Curie temperature decreases with increasing Sm content from 358 K for x = 0–286 K for x = 0.3. We determined the isothermal magnetic entropy changes of all the samples from the magnetization measurements and furthermore measured the adiabatic temperature change of the sample for x = 0.3 directly. The results showed that the adiabatic temperature change, determined using together the entropy change and the specific heat and the value obtained by direct temperature change measurements both give 1.3 K for a magnetic field change of 3 T at about 280 K. We also measured the cyclic adiabatic temperature-change of the sample and the results indicate that the sample undergoes a reversible temperature-change on field-cycling which is essential for magnetic refrigeration.

The study of phase, microstructure, and magnetocaloric properties in LaFe11.6*xSi1.4B0.1 alloys

The effect of Fe on the phase and magnetocaloric property of LaFe11.6*xSi1.4B0.1 alloys with x = 1.0–1.4 have been studied. The results show that the excess of Fe will make the α-Fe phases increase, but the easy corrosion LaFeSi phase reduces in LaFe11.6*xSi1.4B0.1 alloys. All LaFe11.6*xSi1.4B0.1 alloys keep the first-order magnetic phase transition. The saturation magnetizations of LaFe11.6*xSi1.4B0.1 alloys with x > 1 are much higher than LaFe11.6Si1.4B0.1 alloy under 2T magnetic field. This results in the maximum isothermal magnetic entropy changes, and the relative cooling power of LaFe11.6*xSi1.4B0.1 alloys is bigger than for LaFe11.6Si1.4B0.1 alloys.

Giant magnetic coercivity in orthorhombic YNi4Si-type SmNi4Si compound

Magnetic properties, magnetocaloric effect and heat capacity of the YNi4Si-type SmNi4Si compound have been investigated. SmNi4Si exhibits ferromagnetic transition at 17K. Below ~9K, the magnetic isotherms of SmNi4Si show metamagnetic-like behavior with critical field of 20kOe at 5K. Heat capacity measurements of SmNi4Si show the electronic heat capacity coefficient γ=94mJ/(molK2), phonon coefficient β=0.35mJ/(molK4) and Debye temperature TD=310K. The magnetocaloric effect of SmNi4Si is calculated in terms of isothermal magnetic entropy change which is obtained by the isothermal magnetization (ΔSmmagn) and heat capacity measurements (ΔSmheat). Both ΔSmmagn and ΔSmheat reach a maximum of –1.0J/kgK at 17K for a field change of 50kOe and they show positive values for a field change of 20kOe at ~9K. Below 15K, SmNi4Si shows large magnetic hysteresis with considerable remanence. At 5K it exhibits giant coercive field of 58kOe in an applied field of 90kOe.

Effect of Zn on the Magnetic and Magnetocaloric Properties of (0.95)La0.7Ca0.3MnO3/(0.05)Mn1−x Zn x Fe2O4 Composites

We report the structural, magnetic, and magnetocaloric properties of (0.95)La0.7Ca0.3MnO3/(0.05)Mn1−x Zn x Fe2O4 (x = 0.0, 0.1, 0.3, 0.5) composites. Polycrystalline samples of the composite material were prepared using the solid-state reaction method. The phase purity and structure of the samples were confirmed using the X-ray powder diffraction (XRD) method. Scanning electron microscope (SEM) studies of the samples reveal that Mn1−x Zn x Fe2O4 is mainly distributed at the surface and grain boundaries of the perovskite matrix La0.7Ca0.3MnO3. The variation of magnetization (M) as a function of temperature and applied magnetic field was investigated. The M-T data plots indicate a paramagnetic to ferromagnetic transition upon cooling in all samples. The magnetic entropy change was also studied through the examination of measured magnetic isotherms, M (H, T) near Curie temperature T C . A magnetocaloric effect has been estimated in terms of isothermal magnetic entropy change. A maximum entropy change value of 1.72 J/kg K was recorded for a magnetic field change of 3 T with a relative cooling power (RCP) value of 177 J/kg for the (0.95)La0.7Ca0.3MnO3/(0.05)MnFe2O4 composite sample.

Influence of bismuth on magnetism and magnetocaloric properties of LaFe11.6Si1.4 intermetallic compound

Crystal structure, magnetic properties and magnetocaloric effects (MCE) of La1–xBixFe11.4Si1.6 (x=0.0 and 0.1) compounds were investigated by X-ray diffraction and magnetization measurements. The La1–xBixFe11.4Si1.6 compounds presented a cubic NaZn13 type structure. First, the magnetization behavior and the magnetic transition were analyzed in terms of Landau theory. Then, Bi substitution for La in La1–xBixFe11.4Si1.6 compounds led to a decrease in magnetic entropy change () but an increase in Curie temperature (TC) significantly. The significant increase of TC by Bi substitution from 202.5 to 256 K for x=0.0 and x=0.1 respectively was attributed to an increase in the Fe-Fe exchange interactions. Moreover, magnetocaloric effect was calculated in terms of isothermal magnetic entropy change. The maximum values of () of La1–xBixFe11.4Si1.6 for x=0.0 and 0.1 compounds were found to be, respectively, 22.56 and 4.36 J/(kg·K) under an applied magnetic field change of 5 T. For the same applied magnetic field (μ0H=5 T), the relative cooling power (RCP) values were found to vary between 487 and 296 J/kg.