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Sergeenkov, S.; Bougrine, Hassan; Ausloos, Marcel; Gilabert, A.

doi:10.1103/physrevb.60.12322

Cited by 11 publications

(28 citation statements)

References 34 publications

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“…The influence of spin-cluster effect on transport properties is expected to be rather important. Some work has been done on studying various possible scenarios, 41,42 including the splitting of phase transitions due to the occurrence of magnetic clusters.…”

Section: Discussionmentioning

confidence: 99%

Spin-cluster effect and lattice-deformation-induced Kondo effect, spin-glass freezing, and strong phonon scattering in La0.7Ca0.3Mn1−xCrxO3

Zhen

et al. 2005

Journal of Applied Physics

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Besides the Kondo effect observed in dilute magnetic alloys, the Cr-doped perovskite manganate compounds La 0.7 Ca 0.3 Mn 1−x Cr x O 3 also exhibit Kondo effect and spin-glass freezing in a certain composition range. An extensive investigation for the La 0.7 Ca 0.3 Mn 1−x Cr x O 3 ͑x = 0.01, 0.05, 0.10, 0.3, 0.6, and 1.0͒ system on the magnetization and ac susceptibility, the resistivity and magnetoresistance, as well as the thermal conductivity is done at low temperature. The spin-glass behavior has been confirmed for these compounds with x = 0.05, 0.1, and 0.3. For temperatures above T f ͑the spin-glass freezing temperature͒ a Curie-Weiss law is obeyed. The paramagnetic Curie temperature is dependent on Cr doping. Below T f there exists a Kondo minimum in the resistivity. Colossal magnetoresistance has been observed in this system with Cr concentration up to x = 0.6. We suppose that the substitution of Mn with Cr dilutes Mn ions and changes the long-range ferromagnetic order of La 0.7 Ca 0.3 MnO 3 . These behaviors demonstrate that short-range ferromagnetic correlation and fluctuation exist among Mn spins far above T f . Furthermore, these interactions are a precursor of the cooperative freezing at T f . The "double bumps" feature in the resistivity-temperature curve is observed in compounds with x = 0.05 and 0.1. The phonon scattering is enhanced at low temperatures, where the second peak of double bumps comes out. The results indicate that the spin-cluster effect and lattice deformation induce Kondo effect, spin-glass freezing, and strong phonon scattering in mixed perovskite La 0.7 Ca 0.3 Mn 1−x Cr x O 3 .

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Section: Discussionmentioning

confidence: 99%

Spin-cluster effect and lattice-deformation-induced Kondo effect, spin-glass freezing, and strong phonon scattering in La0.7Ca0.3Mn1−xCrxO3

Zhen

et al. 2005

Journal of Applied Physics

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“…(3) revealed that, even though it is possible to qualitatively describe the behavior of magnetization in regions (I) and (III), the mean (average) contribution to M (T ) utterly fails to explain (even qualitatively) the most interesting reentrance region of the M − T diagram. There- fore, based on our previous experience with manganites (which are shown to exhibit strong Gaussian [11] and critical [12] fluctuations both above and below the Curie temperature), we argue that a similar situation may take place in Heusler alloys as well because rather powerful martensitic transformations drastically modifying the domain structure of the alloys would inevitably trigger strong magnetic fluctuations throughout the entire M − T diagram. That is why, it is quite reasonable to assume that, in order to fully understand the magnetic behavior of our sample, in addition to the average magnetizations of the ordered phases (given by Eq.…”

Section: Resultsmentioning

confidence: 99%

“…Namely, the fluctuation-induced contribution to magnetization above (+) and below (−) the critical point T i reads [11,13] …”

Section: Resultsmentioning

confidence: 99%

“…To account for all magnetic changes caused by structural transformations in our sample, we adopt the scenario with multiple order parameters η i , by defining the above-introduced three critical temperatures T i (with T 1 = T CM , T 2 = T M S , and T 3 = T CA ) via the vanishing condition η i (T i ) = 0, separately for three ordered phases marked as i = 1, 2, 3, respectively. The resulting GL functional has the following form [11]:…”

Section: Samples Characterization and Magnetic Measurementsmentioning

confidence: 99%

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DecipheringM–Tdiagram of shape memory Heusler alloys: reentrance, plateau and beyond

Sergeenkov

Córdova

Ari-Gur

et al. 2016

Philosophical Magazine Letters

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We present our recent results on temperature behavior of magnetization observed in N i47M n39In14 Heusler alloys. Three regions can be distinguished in the M −T diagram: (I) low temperature martensitic phase (with the Curie temperature TCM = 140K), (II) intermediate mixed phase (with the critical temperature TMS = 230K) exhibiting a reentrant like behavior (between TCM and TMS), and (III) high temperature austenitic phase (with the Curie temperature TCA = 320K) exhibiting a rather wide plateau region (between TMS and TCA). By arguing that powerful structural transformations, causing drastic modifications of the domain structure in alloys, would also trigger strong fluctuations of the order parameters throughout the entire M − T diagram, we were able to successfully fit all the data by incorporating Gaussian fluctuations (both above and below the above three critical temperatures) into the Ginzburg-Landau scenario.

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“…[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27] In the doping range 0.2 < x < 0.5, these compounds are known to undergo a double magnetic and conductive phase transition under cooling from a paramagnetic (PM) weakly conductive, usually called insulating (I), state to a ferromagnetic (FM) metallic-like (M) state. Thus a Curie temperature T C and a charge carrier localization temperature T MI are respectively defined.…”

Section: Introductionmentioning

confidence: 99%

Magnon-polaron and spin-polaron signatures in the specific heat and electrical resistivity ofLa0.6Y0.1
Ausloos
¹
,
Hubert
²
,
Dorbolo
³

et al. 2002
Phys. Rev. B
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La0.6Y0.1Ca0.3M nO3, an ABO3 perovskite manganite oxide, exhibits a non trivial behavior in the vicinity of the sharp peak found in the resistivity ρ as a function of temperature T in zero magnetic field. The various features seen on dρ/dT are discussed in terms of competing phase transitions. They are related to the M n − O − M n bond environment depending on the content of the A crystallographic site. A Ginzburg-Landau type theory is presented for incorporating concurrent phase transitions. The specific heat C of such a compound is also examined from 50 till 200 K. A log-log analysis indicates different regimes. In the low temperature conducting ferromagnetic phase, a collective magnon signature (C ≃ T 3/2 ) is found as for what are called magnon-polaron excitations. A C ≃ T 2/3 law is found at high temperature and discussed in terms of 1 the fractal dimension of the conducting network of the weakly conducting (so-called insulating) phase and Orbach estimate of the excitation spectral behaviors. The need of considering both independent spin scattering and collective spin scattering is thus emphasized. The report indicates a remarkable agreement for the Fisher-Langer formula, i.e. C ∼ dρ/dT at second order phase transitions. Within the Attfield model, we find an inverse square root relationship between the critical temperature(s) and the total local M n − O − M n strain.

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Estimation of the charge carrier localization length from Gaussian fluctuations in the magneto-thermopower ofLa0.6Y0.1

Cited by 11 publications

References 34 publications

Spin-cluster effect and lattice-deformation-induced Kondo effect, spin-glass freezing, and strong phonon scattering in La0.7Ca0.3Mn1−xCrxO3

Spin-cluster effect and lattice-deformation-induced Kondo effect, spin-glass freezing, and strong phonon scattering in La0.7Ca0.3Mn1−xCrxO3

DecipheringM–Tdiagram of shape memory Heusler alloys: reentrance, plateau and beyond

Magnon-polaron and spin-polaron signatures in the specific heat and electrical resistivity ofLa0.6Y0.1
Ausloos
¹
,
Hubert
²
,
Dorbolo
³

et al. 2002
Phys. Rev. B
Self Cite

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Estimation of the charge carrier localization length from Gaussian fluctuations in the magneto-thermopower ofLa0.6Y0.1

Cited by 11 publications

References 34 publications

Spin-cluster effect and lattice-deformation-induced Kondo effect, spin-glass freezing, and strong phonon scattering in La0.7Ca0.3Mn1−xCrxO3

Spin-cluster effect and lattice-deformation-induced Kondo effect, spin-glass freezing, and strong phonon scattering in La0.7Ca0.3Mn1−xCrxO3

DecipheringM–Tdiagram of shape memory Heusler alloys: reentrance, plateau and beyond

Magnon-polaron and spin-polaron signatures in the specific heat and electrical resistivity ofLa0.6Y0.1Ausloos1, Hubert2, Dorbolo3 et al. 2002Phys. Rev. BSelf Cite

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About

Magnon-polaron and spin-polaron signatures in the specific heat and electrical resistivity ofLa0.6Y0.1
Ausloos
¹
,
Hubert
²
,
Dorbolo
³

et al. 2002
Phys. Rev. B
Self Cite