pith. sign in

arxiv: 1907.02812 · v1 · pith:YY3Z6TA4new · submitted 2019-07-05 · ❄️ cond-mat.str-el

Reentrant spin-glass and transport behavior of Gd4PtAl, a compound with three sites for Gd

Ram Kumar , Jyoti Sharma , Kartik K Iyer , E.V. Sampathkumaran This is my paper

Pith reviewed 2026-05-25 02:12 UTC · model grok-4.3

classification ❄️ cond-mat.str-el
keywords reentrant spin-glassGd4PtAlantiferromagnetic transitionAC susceptibilitymagnetoresistanceintermetallic compoundrare-earth magnetismisothermal remnant magnetization
0
0 comments X

The pith

Gd4PtAl shows reentrant spin-glass behavior in zero field due to competing magnetic interactions on three Gd sites.

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

The study examines magnetization, heat capacity, and transport in the cubic intermetallic Gd4PtAl, which features three distinct crystallographic sites for gadolinium. Data show an antiferromagnetic transition at 64 K, identified by a field-shifting heat-capacity upturn, followed by spin-glass characteristics below 20 K such as frequency-dependent AC susceptibility peaks that are suppressed by DC fields, slow isothermal remnant magnetization decay, and low-field hysteresis. These features together indicate reentrant spin-glass order in zero field arising from the interplay of antiferromagnetic and ferromagnetic components, which in turn produces distinctive electrical resistivity and magnetoresistance responses.

Core claim

Gd4PtAl orders antiferromagnetically at 64 K, as established by the field-dependent shift of the heat-capacity anomaly, yet develops reentrant spin-glass features below 20 K in zero field. The spin-glass state is diagnosed by the frequency shift of the AC susceptibility peak near 20 K, its suppression under applied DC field, time-dependent decay of the isothermal remnant magnetization, and the appearance of low-field hysteresis exclusively below 20 K. The three Gd sites in the cubic structure permit competing antiferromagnetic and ferromagnetic interactions whose balance changes with temperature and field, thereby producing the observed peculiar transport properties.

What carries the argument

Reentrant spin-glass state produced by competing antiferromagnetic and ferromagnetic components on three distinct Gd sites in the cubic F-43m structure.

If this is right

  • Electrical resistivity displays unusual temperature dependence arising from the competing magnetic components.
  • Magnetoresistance shows distinctive field and temperature evolution tied to the reentrant transition.
  • Heat capacity confirms the antiferromagnetic character at 64 K but lacks any clear signature at the lower spin-glass feature.
  • Application of a DC field suppresses the spin-glass signatures around 20 K while shifting the higher transition.

Where Pith is reading between the lines

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

  • The presence of three Gd sites may provide a structural motif that favors tunable magnetic frustration in related cubic intermetallics.
  • Single-crystal measurements could reveal whether the transport anomalies arise from anisotropic scattering by the frozen spins.
  • Chemical substitution on the Pt or Al sites might shift the balance between the two magnetic components and alter the reentrant temperature.
  • Neutron diffraction below 20 K could directly test whether short-range frozen correlations coexist with the higher-temperature antiferromagnetic order.

Load-bearing premise

The observed frequency dependence of the AC susceptibility peak near 20 K, its field suppression, slow remnant magnetization decay, and low-field hysteresis are enough to establish spin-glass order rather than impurity phases, superparamagnetism, or domain effects.

What would settle it

Absence of any frequency shift in the AC susceptibility peak near 20 K, or the appearance of a sharp heat-capacity anomaly at that temperature, would undermine the spin-glass assignment.

Figures

Figures reproduced from arXiv: 1907.02812 by E.V. Sampathkumaran, Jyoti Sharma, Kartik K Iyer, Ram Kumar.

Figure 1
Figure 1. Figure 1: X-ray diffraction pattern of Gd4PtAl. The continuous line through the data points is the result of Rietveld refinement. The difference between the experimental pattern and the line obtained by fitting are shown at the bottom (in blue). The fitting parameters (including R-factors) including χ (which here represents goodness of fit) are also shown [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
read the original abstract

We report temperature (T) dependence (2-330 K) of DC and AC magnetization (M), isothermal remnant magnetization (M_IRM), heat capacity (C), electrical resistivity (rho), and magnetoresistance (MR) of a ternary intermetallic compound, Gd4PtAl, crystallizing in a cubic (space group F-43m) structure. In this structure, there are three sites for the rare-earth. The magnetization data reveal that, in addition to a magnetic transition at 64 K, there is another magnetic feature below 20 K. The C(T) data reveal an upturn below 64 K, shifting to a lower temperature with increasing field, which establishes that the onset of magnetic order is of an antiferromagnetic type. However, there is no worthwhile feature near 20 K in the C(T) curve. AC susceptibility peak undergoes an observable change with frequency and, in particular, the peak around 20 K gets suppressed with the application of a dc magnetic field; in addition, M_IRM undergoes a slow decay with time and isothermal M exhibits low-field hysteresis below 20 K only, which is typical of spin-glasses. The results overall suggest that this compound is a reentrant spin-glass in zero-field. There are experimental signatures pointing to the existence of both antiferromagnetic and ferromagnetic components, competing with the variation of temperature and magnetic field, as a result of which electrical and magnetoresistance behaviors are peculiar. The results overall suggest this compound exhibits interesting magnetic and transport properties.

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 / 2 minor

Summary. The manuscript presents temperature-dependent DC/AC magnetization, isothermal remnant magnetization, heat capacity, resistivity, and magnetoresistance data on cubic Gd4PtAl (F-43m), which contains three distinct Gd sites. It identifies an antiferromagnetic transition near 64 K from the field-dependent shift of the C(T) upturn and a second feature below 20 K. The latter is interpreted as reentrant spin-glass order on the basis of a frequency-dependent AC susceptibility peak that is suppressed by DC field, slow M_IRM relaxation, and low-field hysteresis below 20 K, with competing AF/FM components invoked to explain the transport anomalies.

Significance. If the reentrant spin-glass assignment is confirmed, the work would supply a multi-technique experimental example of competing interactions in a rare-earth intermetallic with multiple magnetic sublattices, potentially relevant to the broader study of frustration and glassy magnetism in ternary compounds. The absence of a C(T) anomaly at 20 K is consistent with glassy order, and the transport data add a useful dimension.

major comments (2)
  1. [Abstract / Magnetization and AC susceptibility] The central claim of reentrant spin-glass order below ~20 K rests on the frequency shift of the AC susceptibility peak, its DC-field suppression, slow M_IRM decay, and low-field hysteresis (Abstract and magnetization sections). These four signatures are standard but non-diagnostic; they are also produced by superparamagnetic clusters, dilute impurity phases, or domain-wall motion in a canted antiferromagnet. No Mydosh parameter, aging/memory-effect data, or quantitative impurity-phase analysis (e.g., SEM/EDX or Rietveld) is provided to discriminate among these possibilities.
  2. [Heat capacity and discussion] The manuscript notes the lack of a heat-capacity feature near 20 K and the presence of three inequivalent Gd sites, yet does not compare the observed behavior to a non-spin-glass reference compound with similar Gd multiplicity or perform a quantitative test (e.g., field-cooled vs. zero-field-cooled irreversibility line) that would be required to establish the reentrant spin-glass scenario as the required rather than a plausible interpretation.
minor comments (2)
  1. [Abstract] The abstract states that the results 'overall suggest' reentrant spin-glass behavior; this phrasing should be made more precise in the main text by explicitly listing the additional diagnostics that would be needed to confirm the assignment.
  2. [Experimental methods] Sample characterization details (phase purity, lattice parameters from Rietveld refinement, and any impurity-phase limits) are referenced only in passing; these should be expanded with quantitative bounds.

Simulated Author's Rebuttal

2 responses · 2 unresolved

We thank the referee for the detailed and constructive report. We address the major comments point by point below, providing additional context from the manuscript and indicating where revisions will be made.

read point-by-point responses

  1. Referee: The central claim of reentrant spin-glass order below ~20 K rests on the frequency shift of the AC susceptibility peak, its DC-field suppression, slow M_IRM decay, and low-field hysteresis. These four signatures are standard but non-diagnostic; they are also produced by superparamagnetic clusters, dilute impurity phases, or domain-wall motion in a canted antiferromagnet. No Mydosh parameter, aging/memory-effect data, or quantitative impurity-phase analysis (e.g., SEM/EDX or Rietveld) is provided to discriminate among these possibilities.

    Authors: We agree that these criteria are not unique to spin glasses when taken individually. However, in Gd4PtAl the combination with the lack of a heat capacity anomaly at 20 K and the presence of three distinct Gd sites (which promote competing AF and FM interactions as evidenced by the transport data) makes the reentrant spin-glass scenario the most plausible. We will include the Mydosh parameter in the revised manuscript, calculated from the AC susceptibility frequency shift, which falls in the range typical for spin glasses. Aging and memory effect data were not measured in this work. For phase purity, the sample was confirmed by powder X-ray diffraction with Rietveld refinement showing no detectable impurity phases; SEM/EDX was not performed but the sharp nature of the 64 K transition supports high sample quality. We will expand the discussion to address alternative interpretations explicitly. revision: partial

  2. Referee: The manuscript notes the lack of a heat-capacity feature near 20 K and the presence of three inequivalent Gd sites, yet does not compare the observed behavior to a non-spin-glass reference compound with similar Gd multiplicity or perform a quantitative test (e.g., field-cooled vs. zero-field-cooled irreversibility line) that would be required to establish the reentrant spin-glass scenario as the required rather than a plausible interpretation.

    Authors: The absence of a C(T) anomaly is highlighted in the manuscript as supporting glassy rather than conventional long-range order. While we did not perform a direct comparison to a reference compound, the structural uniqueness of Gd4PtAl with its three Gd sites is central to our interpretation of competing interactions. We will add references to other multi-sublattice rare-earth compounds exhibiting similar reentrant behavior in the revised discussion. The DC magnetization data already show ZFC-FC irreversibility below 20 K; we will add a quantitative analysis of the irreversibility line versus field in the revision to provide the suggested test. revision: partial

standing simulated objections not resolved
  • Aging and memory-effect measurements were not performed and cannot be added without new experiments.
  • SEM/EDX analysis for impurity quantification was not conducted.

Circularity Check

0 steps flagged

No circularity: purely experimental measurements with no derivations or fitted predictions

full rationale

This is an experimental report presenting DC/AC magnetization, heat capacity, resistivity and magnetoresistance data on Gd4PtAl. The central claim (reentrant spin-glass behavior below ~20 K) rests on observed features such as frequency shift of the AC peak, its field suppression, slow M_IRM decay and low-field hysteresis. No equations, ansatze, parameter fits, or self-citations are used to derive any result from prior results within the paper; the data are reported directly and the interpretation is offered as one reading of the measurements. The absence of any load-bearing derivation chain means the paper is self-contained against external benchmarks and receives the default non-circularity finding.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

The central claim rests on standard experimental signatures used in the spin-glass literature; no free parameters, ad-hoc axioms, or new entities are introduced in the abstract.

pith-pipeline@v0.9.0 · 5824 in / 1189 out tokens · 25760 ms · 2026-05-25T02:12:25.431123+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

24 extracted references · 24 canonical work pages

  1. [1]

    Pecharsky and K.A

    V.K. Pecharsky and K.A. Gschneidner, Jr. Phys. Rev. Lett. 78, 4494 (1997)

    work page 1997

  2. [2]

    Tsutaoka, T

    T. Tsutaoka, T. Tokunaga, M. Kosaka, Y. Uwatoko, H. Suzuki, H. Kitazawa, and G. Kido, Physica B 294-295, 199 (2001)

    work page 2001

  3. [3]

    Sengupta and E

    K. Sengupta and E. V. Sampathkumaran, J. Phys.: Condens. Mater 18, L401 (2006)

    work page 2006

  4. [4]

    Sampathkumaran, Phys

    Kausik Sengupta and E.V. Sampathkumaran, Phys. Rev. B 73, 020406(R) (2006)

    work page 2006

  5. [5]

    Rayaprol, V

    S. Rayaprol, V. Siruguri, A. Hoser, C. Ritter, and E. V. Sampathkumaran, Phys. Rev. B 90, 134417 (2014)

    work page 2014

  6. [6]

    Tappe, C

    F. Tappe, C. Schwickert, S. Linsinger, and R. Pöttgen, Monatsch. Chem. 142, 1087 (2011)

    work page 2011

  7. [7]

    A. Doan, S. Rayaprol, and R. Pöttgen, J. Phys. Condens. Matter. 19, 076213 (2007)

    work page 2007

  8. [8]

    Kersting, S.F

    M. Kersting, S.F. Matar, C. Schwickert, and R. Pöttgen, Z. Naturforsch. 67b, 61 (2012)

    work page 2012

  9. [9]

    Engelbert and O

    S. Engelbert and O. Janka, Intermetallics, 96, 84 (2018)

    work page 2018

  10. [10]

    Marcano, J

    N. Marcano, J. C. Gómez Sal, J. I. Espeso, L. Fernández Barquín, and C. Paulsen, Phys. Rev. 76, 224419 (2007)

    work page 2007

  11. [11]

    Yamamoto , Atsuhiro Kotani, Hiroshi Nakajima, Ryuji Okazaki , Hiroki Taniguchi, Shigeo Mori, and Ichiro Terasaki, J

    Takafumi D. Yamamoto , Atsuhiro Kotani, Hiroshi Nakajima, Ryuji Okazaki , Hiroki Taniguchi, Shigeo Mori, and Ichiro Terasaki, J. Phys. Soc. Jpn. 85, 034711 (2016)

    work page 2016

  12. [12]

    Sanjay Kumar Upadhyay, Kartik K Iyer and E V Sampathkumaran, J. Phys. Condens. Matter 29, 325601 (2017)

    work page 2017

  13. [13]

    Roy, A.K

    S.B. Roy, A.K. Pradhan, and P. Chaddah, J. Phys.: Condens. Matter. 6, 5155 (1994)

    work page 1994

  14. [14]

    Roy, A.K

    S.B. Roy, A.K. Pradhan, P. Chaddah, and E.V. Sampathkumaran, J. Phys.: Condens. Matter. 9, 2465 (1997)

    work page 1997

  15. [15]

    Nordblad, P

    P. Nordblad, P. Svedlindh, L. Lundgren, and L. Sandlund, Phys. Rev. B 33, 645 (1986)

    work page 1986

  16. [16]

    Binder and A.P

    K. Binder and A.P. Young, Rev. Mod. Phys. 58, 801 (1986)

    work page 1986

  17. [17]

    Spin glasses: An Experimental Introduction,

    J.A. Mydosh, “Spin glasses: An Experimental Introduction,” Taylor and Francis, London, 1993

    work page 1993

  18. [18]

    Mydosh, Rep

    J.A. Mydosh, Rep. Prog. Phys. 78, 052501 (2015)

    work page 2015

  19. [19]

    Manekar, S

    M.A. Manekar, S. Chaudhary, M.K. Mukhopadhyay, K.J. Singh, S.B. Roy, and P. Chaddah, Phys. Rev. 64, 104416 (2001)

    work page 2001

  20. [20]

    Gschneidner, Jr, V.K

    K.A. Gschneidner, Jr, V.K. Pecharsky, and A.O. Tsokol, Rep. Prog. Phys. 68, 1479 (2005)

    work page 2005

  21. [21]

    Mallik, E.V

    R. Mallik, E.V. Sampathkumaran, M. Strecker, and G. Wortmann, Europhys. Lett. 41, 315 (1998); R. Mallik and E.V. Sampathkumaran, Phys. Rev. B 58, 9178 (1998); E.V. Sampathkumaran, Kausik Sengupta, S. Rayaprol, Kartik K Iyer, Th. Doert, and J.P.F. Jemetio, Phys. Rev. Lett. 91, 036603 (2003); Subham Majumdar and E.V. Sampathkumaran, Phys. Rev. Page8 B 61, 1...

    work page 1998

  22. [22]

    Legvold, in ‘Magnetic properties of rare-earth metals’, edited by R.J

    S. Legvold, in ‘Magnetic properties of rare-earth metals’, edited by R.J. Elliot (Plenum, 1972)

    work page 1972

  23. [23]

    Yamada and S

    K. Yamada and S. Takada, Prog. Theor. Phys. 49, 1401 (1973)

    work page 1973

  24. [24]

    Magnetoresistance in metals

    A.B. Pippard, “Magnetoresistance in metals”, (Cambridge University Press, 1972). Figure 1: X-ray diffraction pattern of Gd4PtAl. The continuous line through the data points is the result of Rietveld refinement. The difference between the experimental pattern and the line obtained by fitting are shown at the bottom (in blue). The fitting parameters (includ...

    work page 1972