scholarly journals Single Crystal Heat Capacity Measurement of Charge Glass Compound θ-(BEDT-TTF)2CsZn(SCN)4 Performed under Current and Voltage Application

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1060
Author(s):  
Kosei Hino ◽  
Tetsuya Nomoto ◽  
Satoshi Yamashita ◽  
Yasuhiro Nakazawa
Keyword(s):  
Heat Capacity ◽  
Single Crystal ◽  
Relaxation Process ◽  
Cooling Power ◽  
Capacity Measurement ◽  
Time Profiles ◽  
Voltage Application ◽  
Relaxation Calorimetry ◽  
Heat Capacity Measurements ◽  
Non Equilibrium

Heat capacity measurements of θ-(BEDT-TTF)2CsZn(SCN)4 in its non-equilibrium electronic states induced by applying electric currents and voltages were performed by a modified relaxation calorimetry technique. We developed a single crystal heat capacity measurements system by which the Joule heating produced in samples by external currents and voltages can be balanced with the cooling power to make a non-equilibrium steady state. Although temperature versus time profiles in the relaxation process in calorimetry can be obtained as exponential curves as in the usual relaxation technique, we found that the change of resistivity that occurs during the heating and relaxation process should be taken into account in analyzing the data. By correcting this factor in the analyses, we succeeded in evaluating absolute values of Cp(I) and Cp(V) in these non-equilibrium states. The experiments up to 150 μA and the constant voltage of 20 mV do not induce visible change in the structure of the Boson peak in CpT−3 vs. T suggestive of the glassy ground state of phonons. Although the suppression of the short-range fluctuations of the charge density has been reported, it does not seriously affect the glassy phonons in this current range.

Phase transition of pyridinium tetrachloroiodate(III), PyHICl4, studied by a single crystal X-ray analysis and dielectric and heat capacity measurements

2007 ◽  
Vol 826 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Tetsuo Asaji ◽  
Kazuo Eda ◽  
Hiroki Fujimori ◽  
Toshinobu Adachi ◽  
Takayoshi Shibusawa ◽  
...  
Keyword(s):  
Phase Transition ◽  
Heat Capacity ◽  
Single Crystal ◽  
X Ray ◽  
Heat Capacity Measurements

Rotational tunneling of methyl groups and the electronic heat capacity of EtMe3Sb[Pd(dmit)2]2 under magnetic fields

2016 ◽  
Vol 30 (13) ◽  
pp. 1642007
Author(s):  
Satoshi Yamashita ◽  
Masayuki Yoshizumi ◽  
Hiroki Akutsu ◽  
Yasuhiro Nakazawa
Keyword(s):  
Heat Capacity ◽  
Magnetic Fields ◽  
Spin Glasses ◽  
Methyl Groups ◽  
Spin Liquid ◽  
Electronic Heat Capacity ◽  
Capacity Measurement ◽  
Electronic Heat ◽  
Heat Capacity Measurements ◽  
The Stability

In order to discuss the stability of the gapless features in the spin liquid state against magnetic fields, we report results and analyses of low-temperature heat capacity measurements of EtMe3Sb[Pd(dmit)2]2 under magnetic fields. The large upturn of [Formula: see text] at 0 T observed previously in EtMe3Sb[Pd(dmit)2]2 can be attributed to the rotational tunneling of the methyl groups in the counter cations and this upturn is suppressed by applying magnetic fields. The phenomenological resemblance of the feature under magnetic field was confirmed by comparative discussion of heat capacity measurement of metal complex of [Cu(acac)(OCH[Formula: see text]]2 having similar methyl groups. The gapless character evidenced by the finite electronic heat capacity coefficient, [Formula: see text] was found to be retained upon applying 17 T in EtMe3Sb[Pd(dmit)2]2, which means that spin liquid ground state is stable against high magnetic fields. The finite [Formula: see text] in the spin liquid compounds is considered to be related to a kind of density of states in spin excitations rather than those determined by disorders such as spin glasses.

1,2,4-Triazole Complexes XIV

1980 ◽  
Vol 35 (12) ◽  
pp. 1387-1389
Author(s):  
D. W. Engelfriet ◽  
W. L. Groeneveld ◽  
G. M. Nap
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Single Crystal ◽  
Specific Heat ◽  
Magnetic Energy ◽  
Series Expansions ◽  
Exchange Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Capacity Measurements

Abstract Heat capacity measurements on Mn(trz)2(NCS)2 in the range 1 - 90 K are reported. A λ-anomaly is found at Tc = 3.292(6) K. From a comparison of the high-temperature specific heat to the predictions from series expansions the intralayer exchange constant is found to be J/k = 0.245(5) K. From the total magnetic energy involved in the transition the value J/k = - 0.254(8) K is calculated. These results compare favourably with previous data from susceptibility measurements.From very recent X-ray diffraction experiments on a single crystal the space group is found to be Pbcn instead of Aba2, as was reported previously.

HEAT CAPACITY MEASUREMENTS ON THE DILUTED ISING SYSTEM Cs3CopZn1-pCl5

1971 ◽  
Vol 32 (C1) ◽  
pp. C1-1008-C1-1009 ◽  
Author(s):  
E. LAGENDIJK ◽  
W. J. HUISKAMP ◽  
P. F. BONGERS
Keyword(s):  
Heat Capacity ◽  
Ising System ◽  
Heat Capacity Measurements

Experimental Study on the Specific Heat Capacity Measurement of Water-Based Al2O3-Cu Hybrid Nanofluid by using Differential Thermal Analysis Method

2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermophysical Properties ◽  
Volume Concentration ◽  
Pure Water ◽  
Heat Capacity Measurement ◽  
Experimental Results ◽  
Hybrid Nanofluid ◽  
Capacity Measurement

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.

Sign in / Sign up

Export Citation Format

Share Document