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arxiv: 2310.05722 · v1 · pith:SWH7UPRVnew · submitted 2023-10-09 · ❄️ cond-mat.mtrl-sci

Magnetocaloric effect of nanostructured La0.6Sr0.4CoO3

Fabiana Morales Alvarez , Mar\'ia Bel\'en Vigna , Mariano Quintero , Diego G. Lamas , Joaqu\'in Sacanell This is my paper

Pith reviewed 2026-05-24 06:20 UTC · model grok-4.3

classification ❄️ cond-mat.mtrl-sci
keywords magnetocaloric effectLa0.6Sr0.4CoO3nanoparticlesconfinement synthesismagnetic refrigerationCurie temperatureentropy changerelative cooling power
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The pith

Confinement synthesis of La0.6Sr0.4CoO3 produces de-agglomerated nanoparticles with enhanced saturation magnetization, Curie temperature, entropy change, and cooling power.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper examines the magnetic and magnetocaloric behavior of La0.6Sr0.4CoO3 made as nanoparticles inside porous templates. It tracks how different template pore sizes change saturation magnetization, Curie temperature, maximum entropy change, and relative cooling power. The authors link the observed increases directly to the resulting de-agglomerated particle structure. A sympathetic reader would see this as evidence that the confinement route can prepare the material for use in films shaped to fit complex refrigerator geometries.

Core claim

Synthesis of La0.6Sr0.4CoO3 under confinement conditions inside porous templates yields de-agglomerated nanoparticles whose saturation magnetization, Curie temperature, maximum entropy change, and relative cooling power increase with template pore size; these enhancements are attributed to the nanostructure and indicate suitability as an active material for magnetic refrigeration devices.

What carries the argument

Confinement synthesis inside porous templates that produces de-agglomerated nanoparticles and thereby raises the measured values of MS, TC, ΔS, and RCP.

If this is right

  • The de-agglomerated nanoparticles can be formed into films that conform to intricate device geometries.
  • Nanostructured LSC becomes a candidate active material for magnetic refrigeration.
  • Confinement synthesis offers an alternative preparation route whose parameter space (pore size) can be explored for further property tuning.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same template-based route could be applied to other cobaltites or manganites to check whether nanostructuring routinely improves their magnetocaloric figures of merit.
  • If the enhancements scale with particle separation rather than with absolute size, then post-synthesis de-agglomeration steps might reproduce the gains without template confinement.

Load-bearing premise

The measured increases in magnetic and magnetocaloric quantities arise from the nanostructure created by the confinement method rather than from differences in composition, oxygen stoichiometry, or experimental conditions.

What would settle it

Direct side-by-side measurement of saturation magnetization, Curie temperature, entropy change, and cooling power on the nanostructured samples versus bulk La0.6Sr0.4CoO3 prepared by a standard route with matched composition and oxygen content.

Figures

Figures reproduced from arXiv: 2310.05722 by Diego G. Lamas, Fabiana Morales Alvarez, Joaqu\'in Sacanell, Mar\'ia Bel\'en Vigna, Mariano Quintero.

Figure 1
Figure 1. Figure 1: XPD patterns of LSC-200 and LSC-800 samples treated at 1000°C and the calculated [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: SEM image for samples synthesized in templates of a) LSC-200 nm, b) LSC-800 nm. [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Magnetization vs Magnetic Field for LSC samples synthesized with templates of 200 [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Magnetization vs temperature of LSC samples measured at 100 Oe and 1000 Oe. [PITH_FULL_IMAGE:figures/full_fig_p010_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Arrott plot for LSC-200 and LSC-800 samples [PITH_FULL_IMAGE:figures/full_fig_p011_5.png] view at source ↗
Figure 5
Figure 5. Figure 5: Temperature dependent ∆SM curves for (a) LSC-200 and (b) LSC-800 samples with magnetic field of 10000, 20000 and 30000 Oe. With the results for the entropy value ∆S we can evaluate the efficiency of a magnetocaloric material which is the relative cooling power (RCP), which is a measure of magnetic cooling efficiency. This refers to the amount of heat that can be transferred by the material from a cold sour… view at source ↗
Figure 6
Figure 6. Figure 6: Relative cooling power for all samples vs. magnetic field. [PITH_FULL_IMAGE:figures/full_fig_p013_6.png] view at source ↗
read the original abstract

In this study, we investigate the magnetic and magnetocaloric properties of nanostructured La0.6Sr0.4CoO3 (LSC) samples synthesized under confinement conditions within porous templates. Using this method, we obtained de-agglomerated nanoparticles, which provide us with the feasibility of applying them in nanoparticle films that can be tailored to intricate geometries. We specifically explored the impact of pore size of the template on key parameters including saturation magnetization (MS), Curie temperature (TC), maximum entropy change ({\Delta}S), and relative cooling power (RCP). Our findings reveal enhancements in those quantities, that are likely to be related with the nanostructure of the samples, indicating the potential of nanostructured LSC as an active material for magnetic refrigeration devices. Our alternative approach of synthesizing magnetocaloric materials under confinement conditions presents an exciting prospect for future research and development in the field.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript reports synthesis of nanostructured La0.6Sr0.4CoO3 (LSC) by confinement within porous templates of varying pore sizes, yielding de-agglomerated nanoparticles. Magnetic and magnetocaloric measurements are presented for saturation magnetization (MS), Curie temperature (TC), maximum entropy change (ΔS), and relative cooling power (RCP), with the central claim that observed enhancements in these quantities are attributable to the nanostructure and indicate potential for magnetic refrigeration applications.

Significance. If the attribution to nanostructure holds after proper controls, the confinement-synthesis route could offer a practical method for producing de-agglomerated magnetocaloric nanoparticles suitable for complex geometries. The work does not, however, supply machine-checked proofs, parameter-free derivations, or falsifiable predictions that would strengthen its assessment.

major comments (2)
  1. [Abstract] Abstract: the claim that enhancements in MS, TC, ΔS and RCP are 'likely to be related with the nanostructure of the samples' and 'pore size of the template' is load-bearing, yet the manuscript supplies no evidence (e.g., EDX, XPS or TGA data) that La/Sr ratio and oxygen stoichiometry are identical across template sizes. Cobaltites are known to be acutely sensitive to both parameters; without such controls the nanostructure explanation cannot be isolated from possible compositional drift.
  2. [Results] Results section: no data tables, error bars, baseline comparisons to bulk LSC, or statistical tests are referenced, so the magnitude and reproducibility of the reported enhancements cannot be evaluated from the provided information.
minor comments (1)
  1. [Abstract] Abstract: the phrase 'enhancements in those quantities' is stated without numerical values or figure references, reducing clarity.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the careful reading and constructive comments. We address the two major comments point by point below, indicating where revisions will be made to improve the manuscript.

read point-by-point responses

  1. Referee: [Abstract] Abstract: the claim that enhancements in MS, TC, ΔS and RCP are 'likely to be related with the nanostructure of the samples' and 'pore size of the template' is load-bearing, yet the manuscript supplies no evidence (e.g., EDX, XPS or TGA data) that La/Sr ratio and oxygen stoichiometry are identical across template sizes. Cobaltites are known to be acutely sensitive to both parameters; without such controls the nanostructure explanation cannot be isolated from possible compositional drift.

    Authors: We agree that cobaltites are compositionally sensitive and that explicit verification is needed to isolate nanostructural effects. In the revised manuscript we will add EDX and XPS measurements (and, if feasible, TGA) on the full set of samples to confirm that La/Sr ratios and oxygen stoichiometry remain constant across the different template pore sizes. This will allow us to strengthen or, if necessary, qualify the attribution to nanostructure. revision: yes

  2. Referee: [Results] Results section: no data tables, error bars, baseline comparisons to bulk LSC, or statistical tests are referenced, so the magnitude and reproducibility of the reported enhancements cannot be evaluated from the provided information.

    Authors: We accept that the absence of tabulated data, error bars, bulk-LSC reference values, and statistical assessment limits evaluation of the reported enhancements. The revised version will include a data table summarizing MS, TC, ΔS and RCP with uncertainties, direct comparisons to literature or measured bulk LSC, and appropriate statistical indicators (e.g., standard deviations from multiple measurements) to allow quantitative assessment of reproducibility and effect size. revision: yes

Circularity Check

0 steps flagged

No circularity: experimental measurements only

full rationale

The paper reports synthesis of La0.6Sr0.4CoO3 nanoparticles via confinement in porous templates of varying pore size, followed by direct measurements of saturation magnetization, Curie temperature, entropy change, and relative cooling power. No equations, parameter fits, derivations, or predictions appear in the abstract or described content. The central claim attributes observed enhancements to nanostructure (pore size and de-agglomeration) based on sample comparisons, without any self-definitional loops, fitted inputs renamed as predictions, or load-bearing self-citations. The work is self-contained experimental reporting; potential confounds like stoichiometry variation are experimental-design issues, not circularity in a derivation chain.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Abstract-only review supplies no explicit free parameters, invented entities, or non-standard axioms; the central claim rests on the domain assumption that confinement synthesis produces the stated nanostructure and that measured property changes are attributable to that nanostructure.

axioms (1)
  • domain assumption Confinement synthesis within porous templates yields de-agglomerated La0.6Sr0.4CoO3 nanoparticles whose magnetic and magnetocaloric properties vary systematically with template pore size.
    Stated directly in the abstract as the basis for the reported enhancements.

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Works this paper leans on

32 extracted references · 32 canonical work pages

  1. [1]

    Raghu Ram, M

    N. Raghu Ram, M. Prakash, U. Naresh, N. Suresh Kumar, T. Sofi Sarmash, T. Subbarao, R. Jeevan Kumar, G. Ranjith Kumar, K. Chandra Babu Naidu, Review on Magnetocaloric Effect and Materials, J. Supercond. Nov. Magn. 31 (2018) 1971–1979. https://doi.org/10.1007/s10948-018-4666-z

    work page doi:10.1007/s10948-018-4666-z 2018

  2. [2]

    Greco, C

    A. Greco, C. Aprea, A. Maiorino, C. Masselli, A review of the state of the art of solid- state caloric cooling processes at room-temperature before 2019, Int. J. Refrig. 106 (2019) 66–88. https://doi.org/10.1016/j.ijrefrig.2019.06.034

    work page doi:10.1016/j.ijrefrig.2019.06.034 2019

  3. [3]

    Pecharsky, K.A

    V.K. Pecharsky, K.A. Gschneidner, Effect of alloying on the giant magnetocaloric effect of Gd5(Si2Ge2), J. Magn. Magn. Mater. 167 (1997) L179–L184. https://doi.org/10.1016/S0304-8853(96)00759-7

    work page doi:10.1016/s0304-8853(96)00759-7 1997

  4. [4]

    Dan’kov, A.M

    S.Y. Dan’kov, A.M. Tishin, V.K. Pecharsky, K.A. Gschneidner, Magnetic phase transitions and the magnetothermal properties of gadolinium, Phys. Rev. B. 57 (1998) 3478–3490. https://doi.org/https://doi.org/10.1103/PhysRevB.57.3478

    work page doi:10.1103/physrevb.57.3478 1998

  5. [5]

    Passanante, L.P

    S. Passanante, L.P. Granja, C. Albornoz, D. Vega, D. Goijman, M.C. Fuertes, Journal of Magnetism and Magnetic Materials Magnetocaloric effect in nanocrystalline manganite bilayer thin films, J. Magn. Magn. Mater. 559 (2022). https://doi.org/10.1016/j.jmmm.2022.169545

    work page doi:10.1016/j.jmmm.2022.169545 2022

  6. [6]

    Phan, S.C

    M.H. Phan, S.C. Yu, Review of the magnetocaloric effect in manganite materials, J. Magn. Magn. Mater. 308 (2007) 325–340. https://doi.org/10.1016/j.jmmm.2006.07.025

    work page doi:10.1016/j.jmmm.2006.07.025 2007

  7. [7]

    Goijman, A.G

    D. Goijman, A.G. Leyva, M. Quintero, Measuring magnetocaloric effect in a phase separated system, Mater. Res. Express. 6 (2018) 026106. https://doi.org/10.1088/2053- 1591/aaf04a

    work page doi:10.1088/2053- 2018

  8. [8]

    Kumar, K

    A. Kumar, K. Kumari, S. Minji, M.K. Sharma, Z. Zhang, S.H. Huh, B.H. Koo, Excellent cooling power in chemically compressed double layer Ruddlesden-Popper ceramics La1.4-xNdxSr1.6Mn2O7 (0.0 ≤ x ≤ 0.15), Ceram. Int. 48 (2022) 4626–4636. https://doi.org/10.1016/J.CERAMINT.2021.10.249

    work page doi:10.1016/j.ceramint.2021.10.249 2022

  9. [9]

    Kumar, A

    A. Kumar, A. Vij, S.H. Huh, J.W. Kim, M.K. Sharma, K. Kumari, N. Yadav, F. Akram, B.H. Koo, Evidence of a moderate refrigerant capacity in cation disordered Ruddlesden- Popper compounds A1.4Sr1.6Mn2O7 (A = La, Pr, Nd) probed with various figures of merit, Curr. Appl. Phys. 49 (2023) 35–44. https://doi.org/10.1016/J.CAP.2023.02.014

    work page doi:10.1016/j.cap.2023.02.014 2023

  10. [10]

    Señarı́s-Rodrı́guez, J.B

    M.A. Señarı́s-Rodrı́guez, J.B. Goodenough, Magnetic and Transport Properties of the System La1-xSrxCoO3-δ (0 < x ≤ 0.50), J. Solid State Chem. 118 (1995) 323–336. https://doi.org/10.1006/jssc.1995.1351

    work page doi:10.1006/jssc.1995.1351 1995

  11. [11]

    Jonker, J.H

    G.H. Jonker, J.H. Van Santen, Magnetic compounds wtth perovskite structure III. ferromagnetic compounds of cobalt, Physica. 19 (1953) 120–130. https://doi.org/10.1016/S0031-8914(53)80011-X

    work page doi:10.1016/s0031-8914(53)80011-x 1953

  12. [12]

    Bhide, D.S

    V.G. Bhide, D.S. Rajoria, C.N.R. Rao, G.R. Rao, V.G. Jadhao, Itinerant-electron ferromagnetism in La1-xSrxCoO3: A Mossbauer study, Phys. Rev. B. 12 (1975) 2832–

    work page 1975

  13. [13]

    https://doi.org/10.1103/PhysRevB.12.2832

    work page doi:10.1103/physrevb.12.2832

  14. [14]

    Mejía Gómez, J

    A.E. Mejía Gómez, J. Sacanell, C. Huck-Iriart, C.P. Ramos, A.L. Soldati, S.J.A. Figueroa, M.H. Tabacniks, M.C.A. Fantini, A.F. Craievich, D.G. Lamas, Crystal structure, cobalt and iron speciation and oxygen non-stoichiometry of La0.6Sr0.4Co1-yFeyO3-δ nanorods for IT-SOFC cathodes, J. Alloys Compd. 817 (2020). https://doi.org/10.1016/j.jallcom.2019.153250

    work page doi:10.1016/j.jallcom.2019.153250 2020

  15. [15]

    Mejía Gómez, J

    A. Mejía Gómez, J. Sacanell, A.G. Leyva, D.G. Lamas, Performance of La0.6Sr0.4Co1−yFeyO3 (y=0.2, 0.5 and 0.8) nanostructured cathodes for intermediate- temperature solid-oxide fuel cells: Influence of microstructure and composition, Ceram. Int. 42 (2015) 3145–3153. https://doi.org/10.1016/j.ceramint.2015.10.104

    work page doi:10.1016/j.ceramint.2015.10.104 2015

  16. [16]

    Menyuk, P.M

    N. Menyuk, P.M. Raccah, K. Dwight, Magnetic Properties of La0.5Sr0.5CoO3, Phys. Rev. 166 (1968) 510–513. https://doi.org/10.1103/PhysRev.166.510

    work page doi:10.1103/physrev.166.510 1968

  17. [17]

    Biswal, T.R

    H. Biswal, T.R. Senapati, A. Haque, J.R. Sahu, Beneficial effect of Mn-substitution on magnetic and magnetocaloric properties of La0.5Sr0.5CoO3 ceramics, Ceram. Int. 46 (2020) 11828–11834. https://doi.org/10.1016/j.ceramint.2020.01.217

    work page doi:10.1016/j.ceramint.2020.01.217 2020

  18. [19]

    Ngan, N.T

    L.T.T. Ngan, N.T. Dang, N.X. Phuc, L. V. Bau, N. V. Dang, D.H. Manh, P.H. Nam, L.H. Nguyen, P.T. Phong, Magnetic and transport behaviors of Co substitution in La0.7Sr0.3MnO3 perovskite, J. Alloys Compd. 911 (2022). https://doi.org/10.1016/j.jallcom.2022.164967

    work page doi:10.1016/j.jallcom.2022.164967 2022

  19. [20]

    P.T. Long, T. V. Manh, T.A. Ho, V. Dongquoc, P. Zhang, S.C. Yu, Magnetocaloric effect in La1-xSrxCoO3 undergoing a second-order phase transition, Ceram. Int. 44 (2018) 15542–15549. https://doi.org/10.1016/j.ceramint.2018.05.216

    work page doi:10.1016/j.ceramint.2018.05.216 2018

  20. [21]

    Saadaoui, R

    F. Saadaoui, R. M’nassri, H. Omrani, M. Koubaa, N.C. Boudjada, A. Cheikhrouhou, RSC Advances Critical behavior and magnetocaloric study in La 0.6 Sr 0.4 CoO 3 cobaltite prepared by a sol–gel process Article, RSC Adv. 6 (2016) 50968–50977. https://doi.org/10.1039/C6RA08132K

    work page doi:10.1039/c6ra08132k 2016

  21. [22]

    Tetean, I.G

    R. Tetean, I.G. Deac, E. Burzo, A. Bezergheanu, Magnetocaloric and magnetoresistance properties of La2/3Sr1/3Mn1-xCoxO3 compounds, J. Magn. Magn. Mater. 320 (2008) 179–182. https://doi.org/10.1016/j.jmmm.2008.02.100

    work page doi:10.1016/j.jmmm.2008.02.100 2008

  22. [23]

    R. Li, P. Kumar, R. Mahendiran, Critical behavior in polycrystalline La0.7Sr0.3CoO3 from bulk magnetization study, J. Alloys Compd. 659 (2016) 203–209. https://doi.org/10.1016/j.jallcom.2015.11.060

    work page doi:10.1016/j.jallcom.2015.11.060 2016

  23. [24]

    Sacanell, A.G

    J. Sacanell, A.G. Leyva, M.G. Bellino, D.G. Lamas, Nanotubes of rare earth cobalt oxides for cathodes of intermediate-temperature solid oxide fuel cells, J. Power Sources. 195 (2010) 1786–1792. https://doi.org/10.1016/j.jpowsour.2009.10.049

    work page doi:10.1016/j.jpowsour.2009.10.049 2010

  24. [25]

    Mejía Gómez, D.G

    A.E. Mejía Gómez, D.G. Lamas, A.G. Leyva, J. Sacanell, Nanostructured La 0.5 Ba 0.5 CoO 3 as cathode for solid oxide fuel cells, Ceram. Int. 45 (2019) 14182–14187. https://doi.org/10.1016/j.ceramint.2019.04.122

    work page doi:10.1016/j.ceramint.2019.04.122 2019

  25. [26]

    Rodríguez-Carvajal ,\ http://dx.doi.org/10.1016/0921-4526(93)90108-I journal journal Physica B: Condensed Matter \ volume 192 ,\ pages 55 ( year 1993 ) NoStop

    J. Rodríguez-Carvajal, Recent advances in magnetic structure determination by neutron powder diffraction, Physica B: Condensed Matter 192 (1993) 55–69. https://doi.org/10.1016/0921-4526(93)90108-I

    work page doi:10.1016/0921-4526(93)90108-i 1993

  26. [27]

    Acuña, J

    L.M. Acuña, J. Peña-Martínez, D. Marrero-López, R.O. Fuentes, P. Nuñez, D.G. Lamas, Electrochemical performance of nanostructured La0.6Sr 0.4CoO3-δ and Sm0.5Sr 0.5CoO3-δ cathodes for IT-SOFCs, J. Power Sources. 196 (2011) 9276–9283. https://doi.org/10.1016/j.jpowsour.2011.07.067

    work page doi:10.1016/j.jpowsour.2011.07.067 2011

  27. [28]

    Kumar, P

    D. Kumar, P. Jena, A.K. Singh, Structural, magnetic and dielectric studies on half-doped Nd0.5Ba0.5CoO3 perovskite, J. Magn. Magn. Mater. 516 (2020) 167330. https://doi.org/10.1016/J.JMMM.2020.167330

    work page doi:10.1016/j.jmmm.2020.167330 2020

  28. [29]

    Biswal, V

    H. Biswal, V. Singh, R. Nath, S. Angappane, J.R. Sahu, Magnetic and magnetocaloric properties of LaCr1-xMnxO3 (x = 0, 0.05, 0.1), Ceram. Int. 45 (2019) 22731–22736. https://doi.org/10.1016/j.ceramint.2019.07.311

    work page doi:10.1016/j.ceramint.2019.07.311 2019

  29. [30]

    Arrott, Criterion for ferromagnetism from observations of magnetic isotherms, Phys

    A. Arrott, Criterion for ferromagnetism from observations of magnetic isotherms, Phys. Rev. 108 (1957) 1394–1396. https://doi.org/10.1103/PhysRev.108.1394

    work page doi:10.1103/physrev.108.1394 1957

  30. [31]

    Banerjee, On a generalised approach to first and second order magnetic transitions, Phys

    B.K. Banerjee, On a generalised approach to first and second order magnetic transitions, Phys. Lett. 12 (1964) 16–17. https://doi.org/10.1016/0031-9163(64)91158-8

    work page doi:10.1016/0031-9163(64)91158-8 1964

  31. [32]

    62, (1999) 1035, doi:10.1088/0034- 4885/62/7/201

    A. Gschneidner, V.K. Pecharsky, A.O. Tsokol, Recent developments in magnetocaloric materials, Reports Prog. Phys. 68 (2005) 1479–1539. https://doi.org/10.1088/0034- 4885/68/6/R04

    work page doi:10.1088/0034- 2005

  32. [33]

    Gschneidner, V.K

    K.A. Gschneidner, V.K. Pecharsky, Magnetocaloric materials, Annu. Rev. Mater. Sci. 30 (2000) 387–429. https://doi.org/10.1146/annurev.matsci.30.1.387

    work page doi:10.1146/annurev.matsci.30.1.387 2000