Searching for a Quantum Critical Point in Rh doped ferromagnetic Ce2.15Pd1.95In0.9

Sereni, J. G.; Giovannini, M.; Berisso, M. Gómez; Saccone, A.

doi:10.1088/1742-6596/391/1/012062

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…The inset of figure 6 represents a schematic magnetic phase diagram, containing the two representative parameters of the physical evolution of this system as a function of Ag doping: the MO temperature T x C ( ) and the C x max ( ) * of the '1 K' anomaly. As mentioned before, the trend of these Ag doped alloys contradicts the general tendency of the Ce 2 Pd 2 In family concerning the increase (decrease) of the number of band electrons in the Pd-X layer that favors a FM (AFM) GS [12,19]. Such a controversy suggests that another factor, rather than the mentioned electronic concentration related to the Fermi energy, dominates the physical behavior of this system.…”

Section: Entropy Gainmentioning

confidence: 75%

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce_2.15(Pd_1−xAg_x)_1.95In_0.9alloys

Sereni

Giovannini

Berisso

et al. 2016

J. Phys.: Condens. Matter

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Low temperature thermal and magnetic measurements performed on ferro-magneticl (FM) alloys of composition Ce2.15(Pd1-x Ag x )1.95In0.9 are presented. Pd substitution by Ag depresses [Formula: see text] from 4.1 K down to 1.1 K for x = 0.5, which is related to the increase of band electrons, with a critical concentration extrapolated to [Formula: see text]. The [Formula: see text] decrease is accompanied by a weakening of the magnetization of the FM phase. At high temperature (T > 30 K) the inverse magnetic susceptibility reveals the presence of robust magnetic moments ([Formula: see text] [Formula: see text]), whereas the low value of the Curie-Weiss temperature [Formula: see text] K excludes any relevant effect from Kondo screening. The specific heat jump at [Formula: see text] decreases accordingly, while an anomaly emerges at a fixed temperature [Formula: see text] K. This unexpected anomaly does not show any associated sign of magnetism checked by AC-susceptibility measurements. Since the total magnetic entropy (evaluated around [Formula: see text]) practically does not change with Ag concentration, the transference of degrees of freedom from the FM component to the non-magnetic T (*) anomaly is deduced. The origin of this anomaly is attributed to an arising magnetic frustration of the ground state and the consequent entropy bottleneck produced by the divergent increasing of density of excitations at low temperature.

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Section: Entropy Gainmentioning

confidence: 75%

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce_2.15(Pd_1−xAg_x)_1.95In_0.9alloys

Sereni

Giovannini

Berisso

et al. 2016

J. Phys.: Condens. Matter

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“…The real test of the results is possible for any quantum phase transitions [9] [10] as T → 0, for example for ferromagnetic Ce 2.15 Pd 1.95 In 0.9 [11], for heavy-fermions systems [15] or for superconductors [10].…”

Section: Discussionmentioning

confidence: 99%

“…This general formula is valid for both finite critical temperature and for the case of T С = 0 K. In the experimental measurements of the critical exponents for the PT's at low temperatures (T → 0) we can expect that the right side of these relations will be less than 2 [1]. The proposed theory can be tested for any quantum phase transitions [8]- [11].…”

Section: Introductionmentioning

confidence: 99%

Violating of the Essam-Fisher and Rushbrooke Relationships at Low Temperatures

Udodov¹

2015

WJCMP

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The Essam-Fisher and Rushbrooke relationships (1963) that connect the equilibrium critical exponents of susceptibility, specific heat and order parameter (and some other relations that follow from the scaling hypothesis) are shown to be valid only if the critical temperature TС > 0 and T → TC. For phase transitions (PT's) with TC = 0 K these relations are proved to be of different form. This fact has been actually observed experimentally, but the reasons were not quite clear. A general formula containing the classical results as a special case is proposed. This formula is applicable to all equilibrium PT's of any space dimension for both TC = 0 and TC > 0. The predictions of the theory are consistent with the available experimental data and do not cast any doubts upon the scaling hypothesis.

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Non-magnetic Anomaly at 1K Arising in Ferromagnetic Ce2.15(Pd1-xAgx)1.95In0.9

et al. 2015

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Magnetic and thermal properties of Ferromagnetic (FM) Ce2.15(Pd1-xAgx)1.95In0.9 alloys were studied in order to determine the Quantum Critical Point (QCP) at TC → 0. The in- crease of band electrons produced by Pd/Ag substitution depresses TC (x) from 4.1K down to TC (x = 0.5)=1.1K, with a QCP extrapolated to xQCP ≥ 0.5. Magnetic susceptibility from T > 30K indicates an effective moment slightly decreasing from μeff =2.56μB to 2.4μB at x=0.5. These values and the paramagnetic temperature θP ≈ -10K exclude significant Kondo screening effects. The TC (x) reduction is accompanied by a weakening of the FM magnetization and the emergence of a specific heat Cm(T) anomaly at T∗ ≈ 1K, without signs of magnetism detected from AC-susceptibility. The magnetic entropy collected around 4K (i.e. the TC of the x = 0 sample) practically does not change with Ag concentration: Sm(4K) ≈ 0.8 Rln2, suggesting a progressive transfer of FM degrees of freedom to the non-magnetic (NM) compo- nent. No antecedent was found concerning any NM anomaly emerging from a FM system at such temperature. The origin of this anomaly is attributed to an entropy bottleneck originated in the nearly divergent power law dependence for T > T∗

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Searching for a Quantum Critical Point in Rh doped ferromagnetic Ce_2.15Pd_1.95In_0.9

Cited by 3 publications

References 8 publications

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce_2.15(Pd_1−xAg_x)_1.95In_0.9alloys

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce_2.15(Pd_1−xAg_x)_1.95In_0.9alloys

Violating of the Essam-Fisher and Rushbrooke Relationships at Low Temperatures

Non-magnetic Anomaly at 1K Arising in Ferromagnetic Ce2.15(Pd1-xAgx)1.95In0.9

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Searching for a Quantum Critical Point in Rh doped ferromagnetic Ce2.15Pd1.95In0.9

Cited by 3 publications

References 8 publications

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce2.15(Pd1−xAgx)1.95In0.9alloys

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce2.15(Pd1−xAgx)1.95In0.9alloys

Violating of the Essam-Fisher and Rushbrooke Relationships at Low Temperatures

Non-magnetic Anomaly at 1K Arising in Ferromagnetic Ce2.15(Pd1-xAgx)1.95In0.9

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Product

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Searching for a Quantum Critical Point in Rh doped ferromagnetic Ce_2.15Pd_1.95In_0.9

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce_2.15(Pd_1−xAg_x)_1.95In_0.9alloys

Competition between ferromagnetism and frustrated antiferromagnetism in quasi 2D Ce_2.15(Pd_1−xAg_x)_1.95In_0.9alloys