AC measurement of heat capacity and magnetocaloric effect for pulsed magnetic fields

Kohama, Yoshimitsu; Marcenat, C.; Klein, Thierry; Jaime, M.

doi:10.1063/1.3475155

Cited by 58 publications

(62 citation statements)

References 51 publications

(120 reference statements)

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“…47 Its magnetoresistance has been reported to be significant just at low temperatures and in high applied magnetic fields. 25,48,49 The Cernox TM is glued using epoxy resin on a fiberglass board equipped with gold contacts to preserve it from mechanical stresses ( Fig. 2(b)).…”

Section: A Adiabatic Temperature-change Probementioning

confidence: 99%

“…[10][11][12][13][14][15] Therefore, the need for novel thermal devices has been continuously pushing scientists to carefully analyze the thermal behavior of magnetic critical processes. During the last years the realization of several in-field calorimetric techniques [16][17][18][19][20][21][22][23][24][25][26][27][28][29] contributed both to a better understanding of the thermomagnetic behavior of the most promising compounds showing first order phase transitions and to encourage the development of new materials. 15,30 Thus, the study of the time and frequency dependence of the MCE constitutes the next step to be taken.…”

Section: Introductionmentioning

confidence: 99%

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Direct magnetocaloric characterization and simulation of thermomagnetic cycles

Porcari

Buzzi²,

Cugini³

et al. 2013

Review of Scientific Instruments

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An experimental setup for the direct measurement of the magnetocaloric effect capable of simulating high frequency magnetothermal cycles on laboratory-scale samples is described. The study of the magnetocaloric properties of working materials under operative conditions is fundamental for the development of innovative devices. Frequency and time dependent characterization can provide essential information on intrinsic features such as magnetic field induced fatigue in materials undergoing first order magnetic phase transitions. A full characterization of the adiabatic temperature change performed for a sample of Gadolinium across its Curie transition shows the good agreement between our results and literature data and in-field differential scanning calorimetry. © 2013 AIP Publishing LLC. [http://dx

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Section: A Adiabatic Temperature-change Probementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Direct magnetocaloric characterization and simulation of thermomagnetic cycles

Porcari

Buzzi²,

Cugini³

et al. 2013

Review of Scientific Instruments

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“…The C p was measured in single crystals of DTN grown from aqueous solutions of thiourea and nickel chloride, with magnetic field applied along the crystalline c-axis. The experimental C p vs H was obtained using an AC technique [17], while sweeping the magnetic field in a 3 He fridge furbished with a 17 T superconducting magnet system at the National High Magnetic Field Laboratory (NHMFL) and the Los Alamos National Laboratory. We also used the standard thermal relaxation method to obtain C v vs T with a dilution refrigerator in a 16 T Physical Properties Measurement System at Quantum Design, Inc. A strongly asymmetric C p vs H is shown in Fig.…”

mentioning

confidence: 99%

Thermal Transport and Strong Mass Renormalization inNiCl2−4SC(NH2)2

et al. 2011

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Several quantum paramagnets exhibit magnetic field-induced quantum phase transitions to an antiferromagnetic state that exists for Hc1 ≤ H ≤ Hc2. For some of these compounds, there is a significant asymmetry between the low-and high-field transitions. We present specific heat and thermal conductivity measurements in NiCl2-4SC(NH2)2, together with calculations which show that the asymmetry is caused by a strong mass renormalization due to quantum fluctuations for H ≤ Hc1 that are absent for H ≥ Hc2. We argue that the enigmatic lack of asymmetry in thermal conductivity is due to a concomitant renormalization of the impurity scattering. PACS numbers: 75.10.Jm, 75.40.Cx The correspondence between a spin system and a gas of bosons has been very fruitful for describing field-induced ordered phases in a large class of quantum paramagnets [1][2][3][4][5]. In this analogy, a magnetic field H plays the role of the chemical potential, which, upon reaching a critical value H c1 , induces a T = 0 Bose-Einstein condensation (BEC), provided that the number of bosons is conserved, the kinetic energy is dominant, and the spatial dimension d > 1. Such a BEC state corresponds to a canted XY magnetic ordering of the spins.At the BEC quantum critical point (QCP), the low-energy bosonic excitations have a quadratic dispersion ω = k 2 /2m * , where m * is the effective mass. This mass is renormalized by quantum fluctuations in the paramagnetic phase H ≤ H c1 . In magnets with H c1 H c2 the renormalization can be expected to be very strong because of the proximity to the magnetic instability. The transition at H c1 should be contrasted with the second BEC-QCP that takes place at the saturation field H c2 [6]. Since the field induced magnetization is a conserved quantity, there are no quantum fluctuations and no mass renormalization for the fully polarized phase above H c2 , i.e., the bare mass m can be obtained from the single-particle excitation spectrum at H ≥ H c2 . Thus, quantum paramagnets are ideal for studying mass renormalization effects because the effective and the bare bosonic masses can be obtained from two different QCP's that occur in the same material.Here we present theoretical and experimental evidence for a strong mass renormalization effect, m/m * 3, in NiCl 2 -4SC(NH 2 ) 2 [referred to as DTN]. We will show that the large asymmetry between the peaks in the low-temperature specific heat, C v (H), in the vicinity of H c1 and H c2 is closely described by analytical and Quantum Monte Carlo (QMC) calculations. The mass renormalization also explains similar asymmetries observed in other properties of DTN, such as magnetization [7], electron spin resonance [8], sound velocity [9,10], and magnetostriction [11]. In a remarkable contrast to these properties, peaks in the low-temperature thermal conductivity, κ, near H c1 and H c2 do not show any substantial asymmetry. We provide an explanation to this dichotomy by demonstrating that the leading boson-impurity scattering amplitude is also renormalized by quantum fluctuation...

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“…[3][4][5][6][7][8][9] Recently, MCE measurements have been combined with pulse magnetic fields and applied to various research in physics at high fields. [10][11][12][13][14][15] In the adiabatic MCE, the temperature change ∆T can be divided into reversible and irreversible terms [16][17][18] as ∆T = ∆T rev + ∆T irr .…”

Section: Introductionmentioning

confidence: 99%

“…The surplus energy can be obtained from µ 0 BdM, which mainly results in the heating as hysteresis loss. 20,21 In previous studies, [3][4][5][6][7][8][9][10][11][12][13][14][15] the authors were mainly interested in ∆T rev , which reveals isentropes in the magnetic fieldtemperature (B-T ) plane. The discontinuity in the isentropes indicates the phase boundary in the B-T phase diagram.…”

Section: Introductionmentioning

confidence: 99%

Irreversible Heating Measurement with Microsecond Pulse Magnet: Example of the α–θ Phase Transition of Solid Oxygen

et al. 2016

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Dissipation inevitably occurs in first-order phase transitions, leading to irreversible heating. Conversely, the irreversible heating effect may indicate the occurrence of the first-order phase transition. We measured the temperature change at the magnetic-field-induced α-θ phase transition of solid oxygen. A significant temperature increase from 13 to 37 K, amounting to 700 J/mol, due to irreversible heating was observed at the first-order phase transition. We argue that the hysteresis loss of the magnetization curve and the dissipative structural transformation account for the irreversible heating. The measurement of irreversible heating can be utilized to detect the first-order phase transition in combination with an ultrahigh magnetic fields generated in a time of µs order.

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AC measurement of heat capacity and magnetocaloric effect for pulsed magnetic fields

Cited by 58 publications

References 51 publications

Direct magnetocaloric characterization and simulation of thermomagnetic cycles

Direct magnetocaloric characterization and simulation of thermomagnetic cycles

Thermal Transport and Strong Mass Renormalization inNiCl2−4SC(NH2)2

Irreversible Heating Measurement with Microsecond Pulse Magnet: Example of the α–θ Phase Transition of Solid Oxygen

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