Structure, magnetic and magnetocaloric properties of new nanocrystalline (Pr,Dy)Fe9 compounds

Guetari, R.; Bartoli, T.; Cizmas, C.B.; Mliki, N.; Bessaïs, L.

doi:10.1016/j.jallcom.2016.05.170

“…The b coefficient including the elastic and the magnetoelastic terms of free energy determines the type of magnetic phase transition [52]. If the b coefficient is positive at TC, it is second order [53]. Around TC, the value of the b coefficient is positive for the samples as seen from Figs.…”

Section: Resultsmentioning

confidence: 90%

Role of nickel doping on magnetocaloric properties of La0.7Sr0.3Mn1−xNixO3 manganites

Çetin

¹

,

Akça

²

,

Aslan

³

et al. 2021

J Mater Sci: Mater Electron

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This study reports the effect of Ni substitution for Mn on structural, magnetic and magnetocaloric properties of La0.7Sr0.3MnO3 manganite synthesized by sol-gel technique. The structural, morphological and magnetic properties are investigated using x-ray diffractometer (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) systems. XRD results showed that all samples crystallize in rhombohedral structure.Thermomagnetic measurements showed that TC decreases with the addition of Ni from 363 K for x = 0.00 to 324 K for x = 0.06. ΔSM determined by Maxwell's relations and Landau theory gave compatible results in the transition temperature and region above. ΔSM max values were determined as 4.52, 4.51, 4.41 and 3.90 Jkg -1 K -1 for x = 0.00, 0.02, 0.04 and 0.06 at 5T, respectively. The Arrott plots and the scaling analysis of ΔSM, which collapsed on a single curve, showed that magnetic transitions are second order.

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“…This section presents a systematic study of the behavior of the universal curve for magnetic entropy change ( ) to confirm the order of magnetic phase transition in TL-LSMO-0.3. A universal curve should be constructed for field-dependent only in case of second-order phase transition 38 – 42 . The existence of a universal curve is based on the formalism that the equivalent points of the different curves calculated for different magnetic fields should collapse on a single curve 38 – 42 .…”

Section: Entropy Analysismentioning

confidence: 99%

“…A universal curve should be constructed for field-dependent only in case of second-order phase transition 38 – 42 . The existence of a universal curve is based on the formalism that the equivalent points of the different curves calculated for different magnetic fields should collapse on a single curve 38 – 42 . If TL-LSMO-0.3 shows a second-order magnetic phase transition, all the curves will collapse on a single universal curve.…”

Section: Entropy Analysismentioning

confidence: 99%

Magnetism in quasi-two-dimensional tri-layer La2.1Sr1.9Mn3O10 manganite

Tiwari

¹

,

Kumar

²

,

Chauhan

³

et al. 2021

Sci Rep

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The tri-layer La$$_{3-3x}$$ 3 - 3 x Sr$$_{1+3x}$$ 1 + 3 x Mn$$_{3}$$ 3 O$$_{10}$$ 10 manganites of Ruddlesden–Popper (RP) series are naturally arranged layered structure with alternate stacking of ω-MnO$$_2$$ 2 (ω = 3) planes and rock-salt type block layers (La, Sr)$$_2$$ 2 O$$_2$$ 2 along c-axis. The dimensionality of the RP series manganites depends on the number of perovskite layers and significantly affects the magnetic and transport properties of the system. Generally, when a ferromagnetic material undergoes a magnetic phase transition from ferromagnetic to paramagnetic state, the magnetic moment of the system becomes zero above the transition temperature (T$$ _{C} $$ C ). However, the tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 shows non-zero magnetic moment above T$$ _{C} $$ C and also another transition at higher temperature T$$ ^{*} \approx $$ ∗ ≈ 263 K. The non-zero magnetization above T$$ _{C} $$ C emphasizes that the phase transition in tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 not a ferromagnetic to paramagnetic state. We show here the non-zero magnetic moment above T$$ _{C} $$ C is due to the quasi-two-dimensional nature of the tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 manganite. The scaling of the magnetic entropy change confirms the second-order phase transition and the critical behavior of phase transition has been studied around T$$_C$$ C to understand the low dimensional magnetism in tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 . We have obtained the critical exponents for tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 , which belong to the short-range two-dimensional (2D)-Ising universality class. The low dimensional magnetism in tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 manganite is also explained with the help of renormalization group theoretical approach for short-range 2D-Ising systems. It has been shown that the layered structure of tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 results in three different types of interactions intra-planer ($$ J_{ab} $$ J ab ), intra-tri-layer ($$ J_{c} $$ J c ) and inter-tri-layer ($$ J' $$ J ′ ) such that $$ J_{ab}> J_{c}>> J' $$ J ab > J c > > J ′ and competition among these give rise to the canted antiferromagnetic spin structure above T$$ _{C} $$ C . Based on the similar magnetic interaction in bi-layer manganite, we propose that the tri-layer La$$_{2.1}$$ 2.1 Sr$$_{1.9}$$ 1.9 Mn$$_{3}$$ 3 O$$_{10}$$ 10 should be able to host the skyrmion below T$$ _{C} $$ C due to its strong anisotropy and layered structure.

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“…The magnetocaloric effect (MCE) has attracted much attention in some fields because of its potential advantages of environmental protection and energy saving. , It is found that the Gd 3+ -base metal complex always exhibits a huge magnetocaloric effect, due to their low spin excitation state and high spin ground state in Gd 3+ ions, − which has led to research of magnetic materials . In recent years, a series of multicore Gd clusters with considerable MCEs have been reported, including high-nuclear heterometallic metal-Gd(III) clusters and pure Gd(III)-clusters, such as Ni 10 Gd 42 , Co 10 Gd 42 , Ni 12 Gd 36 , Ni 64 Gd 78 , Ni 64 Gd 96 , Gd 24 , Gd 27 , Gd 36 , Gd 37 , Gd 38 , Gd 48 , and Gd 140 , which may indicate that Gd clusters are potential candidates in the field of magnetic refrigeration materials.…”

Section: Introductionmentioning

confidence: 99%

The Stepwise Formation of {Gd₄} Clusters with Magnetocaloric Effect, Accompanied by In Situ Condensation Cyclization Reactions

Pan

¹

,

Wu

²

,

He

³

et al. 2022

Crystal Growth & Design

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Accompanied by condensation cyclization reactions in solvothermal conditions, three Gd(III) tetranuclear clusters {[Gd4(L x )2(μ3-OH)2(NO3)2(Ac)6]} (x = 1, 2, and 3 for 1, 2, and 3, respectively) were isolated and characterized, wherein, L1–3 were in situ synthesized from bis[3-(pyridin-2-yl)-1H-1,2,4-triazole-5-yl]methane (bptm), 5-bptm (bis[3-(5-methylpyridin-2-yl)-1H-1,2,4-triazole-5-yl]methane), and 4-bptm (bis[3-(4-methylpyridin-2-yl)-1H-1,2,4-triazole-5-yl]methane) in the presence of GdIII ions, respectively. The step-by-step formation process (bptm → L1 → Gd1(L1)1 → Gd2(L1)1 → Gd2(L1)2 → Gd3(L1)2 → Gd4(L1)2) of the tetranuclear clusters in 1 was tracked by mass spectrometry technology. The study of their magnetic properties showed that 1–3 displayed significant magnetocaloric effects with the −ΔS m values of 29.25–29.64 J K–1 kg–1.

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Structure, magnetic and magnetocaloric properties of new nanocrystalline (Pr,Dy)Fe9 compounds

Cited by 15 publications

References 26 publications

Role of nickel doping on magnetocaloric properties of La0.7Sr0.3Mn1−xNixO3 manganites

Role of nickel doping on magnetocaloric properties of La0.7Sr0.3Mn1−xNixO3 manganites

Magnetism in quasi-two-dimensional tri-layer La2.1Sr1.9Mn3O10 manganite

The Stepwise Formation of {Gd₄} Clusters with Magnetocaloric Effect, Accompanied by In Situ Condensation Cyclization Reactions

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Structure, magnetic and magnetocaloric properties of new nanocrystalline (Pr,Dy)Fe9 compounds

Cited by 15 publications

References 26 publications

Role of nickel doping on magnetocaloric properties of La0.7Sr0.3Mn1−xNixO3 manganites

Role of nickel doping on magnetocaloric properties of La0.7Sr0.3Mn1−xNixO3 manganites

Magnetism in quasi-two-dimensional tri-layer La2.1Sr1.9Mn3O10 manganite

The Stepwise Formation of {Gd4} Clusters with Magnetocaloric Effect, Accompanied by In Situ Condensation Cyclization Reactions

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The Stepwise Formation of {Gd₄} Clusters with Magnetocaloric Effect, Accompanied by In Situ Condensation Cyclization Reactions