Magnetic Entropy Change Research Articles

Magnetothermal effect and first-principles calculations of Zn-doped Mn5Ge3-based alloys

This study investigates the compound system Mn5−xZnxGe3 (x = 0.1, 0.2, and 0.3) through experimental investigations and theoretical calculations. Zn doping lowers the Curie temperature and magnetic entropy change of Mn5−xZnxGe3 alloys. Analysis of phenomenological curves, including Landau theories, normalized curves, and Arrott curves during the study of isothermal magnetization curves, reveals a second-order phase transition in this system. Through an extensive investigation of critical behavior using critical isotherm curves and the Kouvel–Fisher (KF) method, the consistency and reliability of these critical indices are validated by the prediction of the scaling theory in the critical region. By scaling the dependence of |ΔSM| on M and applying crucial exponen21t values, an efficient new approach is utilized to calculate the spontaneous magnetization that agrees well with the values deduced from the KF method. Additionally, first-principles calculations reveal that the Mn atoms' 3d orbitals are more significantly close to the Fermi energy level, with Zn doping generally reducing both the electronic density of states and the total magnetic moment of the Mn 3d orbitals. Consequently, the introduction of Zn leads to a decrease in the Mn–Mn atom exchange coupling, resulting in a deterioration of the total exchange interaction. This phenomenon also explains the decrease in the Curie temperature TC due to Zn doping, aligning with experimental observations.

Observation of Griffiths phase and giant magnetocaloric effect in double perovskite oxide RE2FeCrO6 (RE = Gd, Tb, Dy, Er)

AbstractThe magnetic properties of double perovskite oxide RE2FeCrO6 (RE = GD, Tb, Dy, Er) were systematically studied, and the Griffiths phase evolution was observed. In Tb2FeCrO6, Dy2FeCrO6, and Er2FeCrO6, there are antiferromagnetic (AFM)‐ferromagnetic (FM) first‐order phase transition and the Griffiths phase with coexistence of FM and paramagnetic (PM) was observed by the EPR spectra. Gd2FeCrO6 has an AFM–PM second‐order phase transition, and there is no first‐order phase transition in the range of ∆H = 0–50 kOe. As the temperature decreases, all four sets of samples present χ−1 (T) deviates downwards from the Curie–Weiss linear behavior from 0.2 to 5 kOe, corresponding to the typical characteristics of Griffiths phase evolution. In addition, all four sets of samples have excellent magnetocaloric performance. Especially, the Gd2FeCrO6 oxide has giant magnetic entropy change and relative cooling power (−∆SMmax = 30.31 J/kg K and RCP = 312.8 J/kg when ∆H = 50 kOe). From the perspective of low‐temperature magnetic refrigeration application, the present work provides important candidate references for magnetic component researchers.

Crystal structure, magnetic property and cryogenic magnetocaloric effect of Gd4Al2O9 aluminate

Developing magnetic materials with excellent magnetocaloric effect (MCE) is a vital prerequisite for practical magnetic refrigeration (MR) applications. Herein, a single-phased polycrystalline Gd4Al2O9 compound was fabricated using the co-precipitation method, and its structure, magnetic property together with magnetocaloric performance were investigated. The Gd4Al2O9 compound was found to crystallize in the monoclinic structure space group P21/c with lattice parameters a = 7.4852 Å, b = 10.5561 Å, c = 11.1774 Å, β = 108.95° and V=835.3107 Å3, and the constituent elementals had valence states of Gd3+, Al3+ and O2−. Excellent comprehensive MCE performance was observed for the Gd4Al2O9 compound in low-temperature regions. The obtained values of maximal magnetic entropy change, temperature-averaged entropy change (3 K) and relative cooling power under the magnetic flux density change of 0–7 T are 26.31 J/kg·K, 25.09 J/kg·K and 317.05 J/kg. The Gd4Al2O9 compound shows impressive comprehensive MCE performances compared with some recently reported rare earth-based MR materials with prominent performances, meaning that it is a suitable candidate material for low-temperature MR applications.

Magnetocrystalline anisotropy energy of AYbO3 (A= Sr, Ba and Ca) perovskite oxides

First-principles calculations and Monte Carlo simulations were employed to explore the effect of magnetic anisotropy on magnetocaloric properties and the magnetocrystalline anisotropy energy (MAE) of AYbO3 (A = Sr, Ba and Ca) perovskite oxides. The equilibrium lattice constant a0 is calculated AYbO3 (A = Sr, Ba and Ca). The elastic constants and related mechanical quantities such as bulk modulus B, Zener anisotropy factor A and Cauchy pressure Cp were calculated. CaYbO3 and SrYbO3 exhibit the half-metallic characteristic. While BaYbO3 exhibits semiconductor character. Sr, Ba and Ca atoms located in the A site affected the values of magnetocrystalline anisotropy energy (MAE) so changing the sign of the magnetic anisotropy constant in SrYbO3. The magnetic anisotropy shows that the easy axis is along the axis [100] for SrYbO3, CaYbO3 and BaYbO3 respectively. The critical temperature around Tc = 65 K using the MCS method. The isothermal magnetic entropy change was calculated for BaYbO3 under different magnetic fields and magnetic anisotropy. The highest isothermal entropy change obtained at H = 5T and D = 0 is 5.51 J/kg.K. While it’s equal to 8.10 J/kg.T at H = 5T and D =5.

Structure, Optical Properties and Magnetocaloric Effects in Gd3Fe5O12 Garnet Synthesized by Solid State Method

In this work, gadolinium iron garnet (Gd3Fe5O12) was synthesized using the solid-state ceramic method. The structural analysis, confirmed through Rietveld refinement, indicated the formation of a single-phase garnet structure. Scanning electron microscopy studies revealed uniform grain size and homogeneity in the sintered material, while UV-vis absorption studies showed a peak at 300 nm, indicating strong ultraviolet interaction and an optical band gap of 3.64 eV, suggesting optoelectronic potential. The fluorescence emission spectrum shows a band at 435 nm, while the excitation spectrum exhibits bands at 275 and 360 nm. The magnetic measurements demonstrated Gd ion ordering at low temperatures, with a compensation temperature around 290 K. Arrott plots confirmed the second-order magnetic phase transition. Importantly, Gd3Fe5O12 exhibited both normal and inverse magnetocaloric effects, with a maximum magnetic entropy change of 1.05 J kg–1 K–1 at 230 K under 9 T magnetic field. These properties indicate Gd3Fe5O12 material as a promising candidate for magnetic refrigeration and optoelectronic applications.

Optimizing Room‐Temperature Thermoelectric and Magnetocaloric Performance via Constructing Multi‐Scale Interfacial Phases in LaFeSi/BiSbTe Thermo‐Electro‐Magnetic Refrigeration Materials

AbstractFabricating a thermo‐electro‐magnetic material that exhibits simultaneously excellent magnetocaloric (MC) and thermoelectric (TE) performance is challenging since the interfacial reaction causes severe deterioration of MC and TE performance. In this work, a construction of multi‐scale interfaces in LaFe10.4Co0.8Si1.8/Bi0.5Sb1.5Te3 (LFS/BST) composites is realized by adopting a low‐temperature high‐pressure sintering strategy. It is revealed in the atomic‐scale that the interfacial reaction between LFS and BST leads to the formation of (Fe,Co)(Sb,Te)2 micro‐grains and LaTe2 nano‐grains, and the latter form low‐mismatch phase boundaries with LFS matrix. Benefiting from the multi‐scale interfacial phases, excellent MC performance of LFS is preserved alongside a minor impact on TE properties, e.g., a peak zT of 1.04 and a small decrease of 3.0% in relative cooling power are achieved in the 2%LFS/BST composite. Compared with other thermo‐electro‐magnetic materials, a good trade‐off between MC and TE performance is realized in LFS/BST composites with simultaneously high MC and TE performance. The 20%LFS/BST composite exhibits a room‐temperature zT of 0.46 with large maximum magnetic entropy change and relative cooling power of 0.81 J kg−1 K−1 and 44.83 J kg−1, respectively. This work provides an effective material design for developing the all‐solid‐state MC/TE hybrid refrigeration technique.

Magnetocaloric and Magnetostrictive Properties of the Tb(Co,In)<sub>2</sub> Laves Phases

Multicomponent polycrystalline TbInxCo2–x (with х = 0–0.2) solid solutions are prepared for the first time, and their crystal structure and magnetic, magnetocaloric, and magnetostrictive properties are studied. X-ray diffraction patterns taken at room temperature demonstrate mainly the presence of the cubic C15 Laves phase in all samples. As the indium content increases to x = 0.1, the lattice parameter is found to increase; the further increase in the indium content to х = 0.2 leads to a decrease in the lattice parameter. In this case, the Curie temperature TC monotonically increases to 245 K. The isotheral magnetic entropy change ΔSmag is calculated in accordance with magnetic measurements using the thermodynamic Maxwell’s relation. At a magnetic field change from 0 to 1.8 T, the maximum entropy change monotonically decreases and, for composition with x = 0.2, is 1.8 J/(kg∙К). As the indium content increases to x = 0.05, the volume magnetostriction increases. The further increase in the indium concentration leads to the decrease in the peak values and their shift to high temperatures.

Magnetic properties and magnetocaloric effect in thiospinel Fe1-xCuxCr2S4 (x = 0.0, 0.5) compounds

In this study, we investigate the magnetic and magnetocaloric properties of Cr-based spinel sulphides Fe1-xCuxCr2S4 (x = 0.0 and x = 0.5). The magnetic transition temperature of FeCr2S4 (176 K) increases to 330 K when 50 % of Fe in FeCr2S4 structure is substituted with Cu. Temperature-dependent Zero-Field-Cooled (ZFC) and Field-Cooled (FC) magnetic moment measurements show a paramagnetic (PM) to ferrimagnetic (FiM) phase transition in our samples. Magnetocaloric properties were investigated through magnetization isotherm measurements. The maximum magnetic entropy change values are −2.78 J/kg. K and −2.11 J/kg. K under 5 T magnetic field, for x = 0 and x = 0.5 in Fe1-xCuxCr2S4, respectively. Analysis of phenomenological universal curves and Arrott plots indicate a second-order magnetic transition for both compounds. Consequently, Fe0.5Cu0.5Cr2S4 emerges as a promising candidate for magnetic refrigeration applications due to its considerable high magnetic entropy change and its proximity to room temperature transition.

Excellent Magnetocaloric Properties near 285 K of Amorphous Fe88Pr6Ce4B2 Ribbon

A novel amorphous Fe88Pr6Ce4B2 ribbon with better magnetocaloric properties near 285 K is reported in the present work. The Fe88Pr6Ce4B2 ribbon exhibits a typical second-order ferromagnetic–paramagnetic transition near its Curie temperature (Tc, ~284 K), with a maximum magnetic entropy change (−ΔSmpeak) of ~4.15 J/(kg × K) under 5 T and a maximum adiabatic temperature rise (ΔTad) of ~2.57 K under 5 T, both of which are almost the largest amongst the iron-based metallic glasses with Tc = 285 ± 10 K. The high −ΔSmpeak enables several amorphous hybrids with table-like −ΔSm–T curves to be synthesized by appropriately proportioning the Fe88Pr6Ce4B2 ribbon and other amorphous ribbons with different Tc. The larger average −ΔSm and effective refrigeration capacity, as well as the appropriate temperature range, make the two amorphous hybrids potential candidates for use as refrigerants in household magnetic air conditioners.

Magnetic and magnetocaloric dynamics in [formula omitted] double perovskites: Impact of A and B site variations analyzed through Monte Carlo simulation and Ab initio calculations

We investigate the magnetic and magnetocaloric properties of the double perovskites Sr2FeOsO6,Sr2FeCoO6,Dy2FeOsO6 and Dy2FeCoO6 using a combination of Monte Carlo simulations and Density Functional Theory (DFT). The exchange couplings were calculated using DFT. Sr2FeOsO6 exhibits antiferromagnetic ordering with two transitions at 50 and 150 K, driven by strong antiferromagnetic exchange interactions between Fe³⁺ and Os⁵⁺ ions. In contrast, Sr2FeCoO6 shows ferrimagnetic behavior with a single transition around 75 K, attributed to ferromagnetic coupling between Co2⁺ and Fe³⁺ ions. For the rare-earth-containing compounds, Dy2FeOsO6 demonstrates complex magnetic ordering with transitions at approximately 20 K and 140 K, influenced by the strong spin-orbit coupling of Dy³⁺ ions. Similarly, Dy2FeCoO6 exhibits two transitions at around 60 K and 170 K, reflecting a mix of ferromagnetic and antiferromagnetic interactions involving Dy³⁺, Co2⁺, and Fe³⁺ ions. Sr2FeOsO6 shows a peak magnetic entropy change ΔSm of 0.22 J/kg.K under a 5 T field at 50 K, while Sr2FeCoO6 exhibits a broader peak at 75 K with ΔSm of 1.5 J/kg·K. Dy2FeOsO6 presents significant ΔSm peaks at 20 K and 140 K, reaching 1.9 J/kg·K under a 5 T field. Dy2FeCoO6 displays the highest ΔSm of 4.0 J/kg·K at 60 K.

La-Fe-Si magnetocaloric composite with anisotropic microstructure prepared by hot pressing

In this study, we have proposed an anisotropic microstructure in La-Fe-Si magnetocaloric composites for thermal management. This is vital to the rapid heat exchange and high working efficiency in magnetic refrigerator system. We demonstrate the anisotropic microstructure in composites can be fabricated via powder metallurgy in this work. By adjusting the particle size of the 1:13 phase, the introduced reinforcing phase with rheological property can effectively deform and anisotropic microstructure can be obviously observed. This can be attributed to the tailored stress distribution in cubic-anvil-type pressure apparatus. The element diffusion between the two phases was also discussed in this paper, taking into account the influence of particle size. Such anisotropic microstructure causes some other anisotropic physical properties in the composite, such as mechanical strength. The compressive measurements along the axial direction exhibit superior mechanical properties (~ 3.5% for strain and ~ 350 MPa for strength) compared to those along the radial direction. Attributed to the stress buffer-effect provided by the introduced ductile phase, magnetocaloric effect (magnetic entropy change ~ 7.8 J/kg K) can be maintained in the La-Fe-Si composite.

Effects of Eu3+ doping on the structural, magnetocaloric effect and critical behavior of Ruddlesden-Popper compounds La1.4-xEuxSr1.6Mn2O7 (0 ≤ x ≤ 0.1)

The effects of Eu3+ doping on the structural and magnetocaloric effect of Ruddlesden-Popper compounds La1.4-xEuxSr1.6Mn2O7 (0 ≤ x ≤ 0.1) were investigated. The X-ray diffraction and infrared spectroscopy confirmed that La1.4-xEuxSr1.6Mn2O7 compounds exhibited the tetragonal lattice symmetry (I4/mmm) of the Ruddlesden-Popper phase. The crystal structure of La1.4-xEuxSr1.6Mn2O7 compounds distorted and phase separated as the amount of Eu3+ doping varied. The magnetization-temperature curves demonstrated that La1.4-xEuxSr1.6Mn2O7 compounds display a notable transition temperature attributed to its anisotropic exchange coupling. The maximum magnetic entropy changes (−ΔSMmax) of La1.4-xEuxSr1.6Mn2O7(x = 0, 0.075, and 0.1) compounds are 2.82, 3.12 and 3.40 J/(kg·K) at the 5 T applied magnetic field. Meanwhile, its relative cooling power (RCP) was 186.37, 207.42 and 242.54 J/kg, respectively. The critical behavior of La1.4-xEuxSr1.6Mn2O7 (0≤x≤0.1) compounds was analyzed around Tc, and it was found that the critical index (β = 0.413, γ = 1.020, δ = 3.038) is essentially in line with the mean field theory.

Anisotropic magnetic entropy change and magnetic critical behavior in van der Waals Fe3GaTe2

Fe3GaTe2, with intrinsic magnetism at ambient temperature and high perpendicular magnetic anisotropy, is a promising van der Waals material for 2D-materials-based spintronic devices. Herein, we report the anisotropic magnetocaloric effects and magnetic critical phenomena in Fe3GaTe2 single crystal. Owing to the large anisotropy, magnetic entropy change (−ΔSM) shows anisotropic character with −ΔSMmax of 1.67 J kg−1 K−1 along the c axis and 1.11 J kg−1 K−1 in the ab plane under field change of 5 T. The rotating ΔSM from the ab plane to the c axis reaches 0.67 J kg−1 K−1 at magnetic field of 5 T. By carefully fitting the −ΔSMmax and relative cooling power (RCP), we determine their relationships to be −ΔSMmax∝Hn (n = 0.694(1)) and RCP∝Hm (m = 1.301(3)) for the magnetic field along the c-axis. Further analysis of critical behavior near TC reveals critical exponents β = 0.41(1) at TC = 341.5(1) K, γ = 1.01(1) at TC = 341.6(3) K, and δ = 3.67(15) at TC = 340 K, indicating a three-dimensional complex magnetic exchange.

Advanced Anti-icing and Deicing Strategies for Overhead Power Transmission Lines Based on Giant Magnetocaloric Effect of La0.7Ca0.254Sr0.046MnO3.

Perovskite manganates (AMnO3) exhibit diverse structural, thermal, electrical, and magnetic properties. Their strong magnetocaloric effect (MCE) near the Curie temperature (TC) makes them ideal for magnetic-thermal anti-icing and deicing in power transmission lines. Below TC, ferromagnetic AMnO3 produces heat through multiple mechanisms, with the changing magnetic field induced by the strong AC current, causing heat through magnetic hysteresis and eddy currents, alongside the direct MCE. Above TC, no heating is generated, as MCE is unfavorable, thus preventing additional energy loss at elevated temperatures. In this work, La0.7Ca0.254Sr0.046MnO3 with TC close to 0 °C were synthesized by solid-state reaction. It is found that particle size >10 μm is beneficial for a large MCE, based on the results of particle size dependence of MCE. The resulting maximum magnetic entropy change at 277 K is 7.69 J·kg-1·K-1, and an adiabatic temperature change of 3.87 K at 277 K is achieved under 5 T. The prototype cable is fabricated using a well-established wire drawing process. A climate-simulation chamber is employed for the anti-icing and deicing experiments. The prototype cables demonstrated a strong capability for deicing and anti-icing. This simple and cost-effective prototype cable shows significant potential for mitigating the icing problem of overhead high-voltage power transmission lines.

Tuning the magnetocaloric and structural properties of La0.67Sr0.28Pr0.05Mn1–xCoxO3 refrigeration materials

Abstract The structural, magnetic and magnetocaloric properties of perovskite manganites La0.67Sr0.28Pr0.05Mn1−x Co x O3 (x = 0.05, 0.075 and 0.10) (LSPMCO) are investigated. LSPMCO crystallizes as a rhombohedral structure with R-3c space group. As the Co content increases, the cell volume expands, the Mn–O–Mn bond angle reduces and the length of the Mn–O bond increases. The samples show irregular submicron particles under a Zeiss scanning electron microscopy. The particle size becomes larger with increasing doping. The chemical composition of the samples is confirmed by x-ray photoelectron spectroscopy (XPS). The ferromagnetic (FM) to paramagnetic (PM) phase transition occurs near the Curie temperature (T C), and all transitions are second-order phase transitions (SMOPT) characterized by minimal thermal and magnetic hystereses. Critical behavior analysis indicates that the critical parameters of LSPMCO closely align with those predicted by the mean-field model. The T C declines with Co doping and reaches near room temperature (302 K) at x = 0.075. The maximum magnetic entropy change ( − Δ S M max ) at x = 0.05 is 4.27 J/kg⋅K, and the relative cooling power (RCP) peaks at 310.81 J/K. Therefore, the system holds significant potential for development as a magnetic refrigeration material, meriting further professional and objective evaluation.

Polymeric Manganese(II) Acetate Derivatives: Syntheses, Crystal Structures and Magnetic Properties

AbstractThree novel polymeric Mn(II) acetate derivatives, identified as {[Mn2.5(OH)(CH3COO)4] ⋅ 0.5CH3OH ⋅ 0.5CH3CN}n (1), {[Mn3(CH3CO O)6] ⋅ 0.5CH3CN}n (2) and {Mn1.5K(CH3COO)4}n (3), have been successfully prepared by systematically adjusting the ratio of reactants and using the 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole (Hmmt) as the template agent. These three complexes can be regarded as the different crystalline forms of Mn(CH3COO)2 under different reaction conditions. Single‐crystal X‐ray diffraction analyses revealed that 1 and 2 feature the unique three‐dimensional (3D) framework. For 3, it displays a 2D structure, which is further assembled to form a 3D extended network via the weak hydrogen bond interactions. Magnetic studies confirmed that 1 and 2 show antiferromagnetic interactions, and 1 displays a long‐range ordering phase below the critical temperature (Tc) of 7.8 K. In addition, magnetisation data collected for 1–2 yield low magnetic entropy changes, which can be attributed to the strong antiferromagnetic interactions among the Mn(II) centres.

Critical behavior and tunable magnetocaloric effect in (Gd1-xErx)3Al2 alloys

The magnetic properties, magnetocaloric effect, and the critical behavior near Curie temperature (TC) were systematically studied in a series of (Gd1-xErx)3Al2 (x = 0, 0.1, 0.2, 0.3) alloys. As the Er content increases, both the TC and lattice constant gradually decrease. The maximum magnetic entropy change and refrigerant capacity remain relatively high, ranging from −5.8 to −8.5J/kg K and 209.0 to 290.8 J/kg respectively, for a field change of 5 T. The critical exponents, derived from the field dependence of magnetic entropy change, conform to scaling theory and are consistent with those obtained using the Kouvel–Fisher method. These findings suggest that the reliability of the obtained critical exponents and imply the presence of long-range exchange interactions in (Gd1-xErx)3Al2 alloys.

Large cryogenic magnetocaloric effect in Na5Gd4F(SiO4)4

The adiabatic demagnetization refrigeration based on the magnetocaloric effect of magnetic materials has been regarded as an effective technology to attain sub-Kelvin temperature. In this article, the magnetic properties and MCE of Na5Gd4F(SiO4)4 compound are investigated. Due to the high Gd3+ ion/anion ligand ratio and weak magnetic interaction, Na5Gd4F(SiO4)4 exhibits a large magnetic entropy change of 49.6 J·kg−1·K−1 under magnetic field change of 0–7 T at 2.6 K, which surpasses the commercial magnetic refrigerant Gd3Ga5O12 under the same conditions. Besides, its refrigeration capacity and the relative cooling power under magnetic field change of 0–7 T reaches up to 308.9 J·kg−1 and 406.7 J·kg−1, respectively. These properties indicate that Na5Gd4F(SiO4)4 compound is a promising magnetic refrigeration material.

Magnetocaloric effect, magnetotransport and magnetic properties of polycrystalline Pr(0.65-x)GdxSr0.35MnO3 (x ≤ 0.3) compounds

Polycrystalline Pr0.65-xGdxSr0.35MnO3 (x = 0.01, 0.05, 0.1, 0.2, 0.3) manganites were prepared by conventional solid-state method. Structural analysis has revealed a change in structure with x = 0.2, from Rhombohedral (R-3c) to Orthorhombic (Pbnm) symmetry. Small oxygen deficiency was found in the samples. The electrical measurements revealed typical colossal magnetoresistance (CMR) behavior, with single metal–insulator peak at Tp for all investigated samples. The small polaron hopping (SPH) and variable-range hopping (VRH) models were used to describe the electrical conduction above Tp. Magnetic measurements show an increase in magnetization below the Curie temperature, TC. Values of Tc diminish with increasing Gd3+ content. Isothermal measurements around critical points suggest a possible interaction between the 4f-ions and Mn-sublattice The magnetic critical behavior analysis established the tri-critical mean-field model to be the governing model for the series. Large magnetic entropy change ΔSM at near room temperature (278 K) was exhibited by the x = 0.01 sample at 2.2 J/kgK in μ0ΔH = 1 T and 5.36 J/kgK in μ0ΔH = 4 T. The largest |ΔSM| value was shown by the x = 0.1 sample. The values of the relative cooling power (RCP) and the temperature-averaged entropy change (TEC) increased with substitution qualifying these compounds as magnetocaloric materials.

The crystal structures, magnetic interactions and cryogenic magnetocaloric effects for NaGdXO4 (X=Si, Ti) compounds

The development of ultra-low temperature magnetic refrigeration technologies demands magnetic refrigeration materials with excellent properties. Hence, improving performances of magnetic refrigerants has always been a significant scientific issue in magnetic refrigeration field. In this article, the relationship of crystal structures, magnetic interactions and magnetocaloric effect (MCE) for NaGdSiO4 and NaGdTiO4 has been investigated. NaGdSiO4 and NaGdTiO4 both crystallizes orthogonal structure, but the significant difference of unit cell parameters and symmetries results in different arrangement of Gd atoms. The distorted crystal structure and weaker magnetic between Gd3+ ions make NaGdSiO4 exhibit larger MCE with the maximum magnetic entropy change (-∆SM) of 49.0J·kg-1·K-1 at 2.8K. Comparably speaking, NaGdTiO4, which is a quasi-triangular antiferromagnet, possesses a stronger magnetic interaction between Gd3+ ions with the maximum -∆SM of 31.9J·kg-1·K-1 at 2.6K. These results confirm the importance of magnetic interactions for magnetic refrigeration materials, and, more broadly, they highlight the significance of crystal structures in that field.