Modulation calorimetry and related techniques

Kraftmakher, Yaakov

doi:10.1016/s0370-1573(01)00031-x

Cited by 98 publications

(56 citation statements)

References 458 publications

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“…In AC calorimetry, an oscillating heat input is supplied to the sample and the resulting temperature oscillation is measured [20]. In its simplest form, the power heating the sample is a constant plus a 4 sine wave.…”

Section: Ac Calorimetrymentioning

confidence: 99%

“…The application of AC calorimetry to measurements, in which the temperature is slowly ramped up, has been used in the past to investigate bulk materials [20,[33][34][35].…”

Section: Scanning Ac Calorimetrymentioning

confidence: 99%

“…Consequently, we assume that a droplet solidifies instantly upon formation of a nucleus. If we assign all droplets with volume v i (and thus a surface or interfacial area of s i ) in the distribution to group i, and if we denote the number of droplets and the nucleation frequency per droplet in that group by n i and , respectively, the rate of nucleation then follows the law of radioactive decay [70] 20) provided the number of droplets is sufficiently large. For bulk nucleation, the expected nucleation frequency is given by 25) where m is the total number of groups in the distribution and V is the total volume of i I droplets at a given time.…”

Section: Application To Nucleation Theorymentioning

confidence: 99%

“…AC calorimetry is well known as a sensitive technique for measuring thermo-physical properties of materials in the presence of heat loss [18][19][20], and is thus often applied in isothermal measurements. In AC calorimetry, an oscillating heat input is supplied to the sample and the resulting temperature oscillation is measured [20]. The amplitude and phase lag of the temperature response provide accurate information on both the heat capacity of the sample and its heat loss to the environment.…”

Section: Introductionmentioning

confidence: 99%

“…If the oscillation frequency is high enough, the contribution of the heat loss vanishes and the measurement can be regarded as adiabatic [20]. When AC calorimetry is applied to bulk materials, the relevant frequency range is quite low (~1 Hz), because of the finite size of the sample and the thermal resistance between the sample, heater, and thermometer [17].…”

Section: Introductionmentioning

confidence: 99%

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Scanning AC Nanocalorimetry and Its Applications

Xiao

Vlassak

2016

Fast Scanning Calorimetry

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This thesis presents an AC nanocalorimetry technique that enables calorimetry measurements on very small quantities of materials over a wide range of scanning rates (from isothermal to 3×10^3 K/s), temperatures (up to 1200 K), and environments. Such working range bridges the gap between traditional scanning calorimetry of bulk materials and nanocalorimetry. The method relies on a micromachined nanocalorimeter with negligible thermal lags between heater, thermometer, and sample. The ability to perform calorimetry measurements over such a broad range of scanning rates makes it an ideal tool to characterize the kinetics of phase transformations, reactions at elevated temperatures or to explore the behavior of materials far from equilibrium. We By combining scanning DC and AC nano-calorimetry techniques, we study the nucleation behavior of undercooled liquid Bi at cooling rates ranging from 10^1 to 10^4 K/s. Upon initial melting, the Bi thin-film sample breaks up into isolated islands. The number of islands in a typical sample is sufficiently large that highly repeatable nucleation behavior is observed, despite the stochastic nature of the nucleation process.We establish a data reduction technique to evaluate the nucleation rate from DC and AC calorimetry results. The results show that the driving force for the nucleation of melted Bi is well described by classical nucleation theory over a wide range of cooling rates. The proposed technique provides a unique and efficient way to examine nucleation kinetics v with cooling rates over several orders of magnitude. The technique is quite general and can be used to evaluate reaction kinetics in other materials.Lastly, we apply the scanning AC nanocalorimetry technique to study solid-gas phase reactions by measuring the change in heat capacity of a sample during reaction. We apply this approach to evaluate the oxidation kinetics of thin-film samples of zirconium in air. The results confirm parabolic oxidation kinetics with an activation energy of 0.59±0.03 eV. The nano-calorimetry measurements were performed using a device that contains an array of micromachined nano-calorimeter sensors in an architecture designed for combinatorial studies. We demonstrate that the oxidation kinetics can be quantified using a single sample, thus enabling high-throughput mapping of the composition-dependence of the reaction rate.vi

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Section: Ac Calorimetrymentioning

confidence: 99%

“…The application of AC calorimetry to measurements, in which the temperature is slowly ramped up, has been used in the past to investigate bulk materials [20,[33][34][35].…”

Section: Scanning Ac Calorimetrymentioning

confidence: 99%

Section: Application To Nucleation Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Scanning AC Nanocalorimetry and Its Applications

Xiao

Vlassak

2016

Fast Scanning Calorimetry

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Differential Scanning Calorimetry and Differential Thermal Analysis

Schick

Lexa

Leibowitz

2012

Characterization of Materials

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Differential scanning calorimetry (DSC) and differential thermal analysis (DTA) are effective analytical tools to characterize melting, crystallization, and mesomorphic transitions and to determine the corresponding enthalpy and entropy changes. The glass transition and other effects that show either changes in heat capacity or a latent heat are accessible too. The advantage of DSC and DTA compared to other calorimetric techniques lies in the broad dynamic range regarding heating and cooling rates, including isothermal and temperature‐modulated operation. The broad dynamic range is especially of interest because many materials are commonly used or produced on far from equilibrium routes and transitions are strongly time (rate) dependent.

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Differential AC‐chip calorimeter for glass transition measurements in ultrathin films

Huth

Минаков

Schick

2006

J Polym Sci B Polym Phys

166

186

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A differential AC-chip calorimeter capable of measuring the step in heat capacity at the glass transition in nanometer-thin films is described. Because of the differential setup, pJ/K sensitivity is achieved. Heat capacity can be measured for sample masses below 1 ng in broad temperature range as needed for the study of the glass transition in nanometer-thin polymeric films. Relative accuracy is sufficient to investigate the changes in heat capacity as the step at the glass transition of polystyrene. The step is about 25% of the total heat capacity of polystyrene. The calorimeter allows for the frequency dependent measurement of complex heat capacity in the frequency range from 1 Hz to 1 kHz. The glass transition in thin polystyrene films (50-4 nm) was determined at well-defined experimental time scales. No thickness dependency of the glass transition temperature was observed within the error limits (63 K)-neither at constant frequency (40 Hz) nor for the trace in the activation diagram (1 Hz-1 kHz).

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Modulation calorimetry and related techniques

Cited by 98 publications

References 458 publications

Scanning AC Nanocalorimetry and Its Applications

Scanning AC Nanocalorimetry and Its Applications

Differential Scanning Calorimetry and Differential Thermal Analysis

Differential AC‐chip calorimeter for glass transition measurements in ultrathin films

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