A simple low-temperature adiabatic calorimeter for small samples
A simple adiabatic calorimeter has been made to investigate the heat capacity of small samples (≤ 1 cm³) of carbon nanomaterials in the temperature range from 1 to 300 K. It makes possible: i) short-time mounting of a sample; ii) doping of samples with gases directly in the calorimeter; iii) short-t...
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Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2011
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| Цитувати: | A simple low-temperature adiabatic calorimeter for small samples / M.I. Bagatskii, V.V. Sumarokov, A.V. Dolbin // Физика низких температур. — 2011. — Т. 37, № 5. — С. 535–538. — Бібліогр.: 4 назв. — англ. |
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irk-123456789-1185512017-05-31T03:09:11Z A simple low-temperature adiabatic calorimeter for small samples Bagatskii, M.I. Sumarokov, V.V. Dolbin, A.V. 8th International Conference on Cryocrystals and Quantum Crystals A simple adiabatic calorimeter has been made to investigate the heat capacity of small samples (≤ 1 cm³) of carbon nanomaterials in the temperature range from 1 to 300 K. It makes possible: i) short-time mounting of a sample; ii) doping of samples with gases directly in the calorimeter; iii) short-time cooling of a sample down to helium temperatures. The adiabatic calorimeter is suitable to place into a helium vessel of a portable Dewar or a helium cryostat. The heat capacity of the fullerit sample has been measured in the temperature range from 1 to 30 K. 2011 Article A simple low-temperature adiabatic calorimeter for small samples / M.I. Bagatskii, V.V. Sumarokov, A.V. Dolbin // Физика низких температур. — 2011. — Т. 37, № 5. — С. 535–538. — Бібліогр.: 4 назв. — англ. 0132-6414 PACS: 81.05.U–, 65.40.Ba http://dspace.nbuv.gov.ua/handle/123456789/118551 en Физика низких температур Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
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8th International Conference on Cryocrystals and Quantum Crystals 8th International Conference on Cryocrystals and Quantum Crystals |
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8th International Conference on Cryocrystals and Quantum Crystals 8th International Conference on Cryocrystals and Quantum Crystals Bagatskii, M.I. Sumarokov, V.V. Dolbin, A.V. A simple low-temperature adiabatic calorimeter for small samples Физика низких температур |
| description |
A simple adiabatic calorimeter has been made to investigate the heat capacity of small samples (≤ 1 cm³) of carbon nanomaterials in the temperature range from 1 to 300 K. It makes possible: i) short-time mounting of a sample; ii) doping of samples with gases directly in the calorimeter; iii) short-time cooling of a sample down to helium temperatures. The adiabatic calorimeter is suitable to place into a helium vessel of a portable Dewar or a helium cryostat. The heat capacity of the fullerit sample has been measured in the temperature range from 1 to 30 K. |
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Article |
| author |
Bagatskii, M.I. Sumarokov, V.V. Dolbin, A.V. |
| author_facet |
Bagatskii, M.I. Sumarokov, V.V. Dolbin, A.V. |
| author_sort |
Bagatskii, M.I. |
| title |
A simple low-temperature adiabatic calorimeter for small samples |
| title_short |
A simple low-temperature adiabatic calorimeter for small samples |
| title_full |
A simple low-temperature adiabatic calorimeter for small samples |
| title_fullStr |
A simple low-temperature adiabatic calorimeter for small samples |
| title_full_unstemmed |
A simple low-temperature adiabatic calorimeter for small samples |
| title_sort |
simple low-temperature adiabatic calorimeter for small samples |
| publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
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2011 |
| topic_facet |
8th International Conference on Cryocrystals and Quantum Crystals |
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http://dspace.nbuv.gov.ua/handle/123456789/118551 |
| citation_txt |
A simple low-temperature adiabatic calorimeter for small samples / M.I. Bagatskii, V.V. Sumarokov, A.V. Dolbin // Физика низких температур. — 2011. — Т. 37, № 5. — С. 535–538. — Бібліогр.: 4 назв. — англ. |
| series |
Физика низких температур |
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2025-07-08T14:13:38Z |
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| fulltext |
© M.I. Bagatskii, V.V. Sumarokov, and A.V. Dolbin, 2011
Fizika Nizkikh Temperatur, 2011, v. 37, No. 5, p. 535–538
A simple low-temperature adiabatic calorimeter
for small samples
M.I. Bagatskii, V.V. Sumarokov, and A.V. Dolbin
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine
47 Lenin Ave., Kharkov 61103, Ukraine
E-mail: Bagatskii@ilt.kharkov.ua
Received January 27, 2011
A simple adiabatic calorimeter has been made to investigate the heat capacity of small samples (≤ 1 cm3) of car-
bon nanomaterials in the temperature range from 1 to 300 K. It makes possible: i) short-time mounting of a sample;
ii) doping of samples with gases directly in the calorimeter; iii) short-time cooling of a sample down to helium tem-
peratures. The adiabatic calorimeter is suitable to place into a helium vessel of a portable Dewar or a helium cryos-
tat. The heat capacity of the fullerit sample has been measured in the temperature range from 1 to 30 K.
PACS: 81.05.U– Carbon/carbon-based materials;
65.40.Ba Heat capacity.
Keywords: low-temperature adiabatic calorimeter, heat capacity of fullerite C60.
We describe a rather simple adiabatic calorimeter to
study the influence of gas admixture on the heat capacity
of small samples of carbon nanomaterials. The size of the
samples is small: ≤10 mm in diameter with the volume of
≤1 cm3. The calorimeter was operated in temperature
range 1–300 K.
The schematic view of the low-temperature part of the
adiabatic calorimeter is shown in Fig. 1. Test sample 5 is
mounted in calorimeter 6. The calorimeter is a thin-walled
copper cup (≈ 4 mm high, inner diameter ≈ 12 mm) soldered
to a copper-foil shell (0.03 mm thick). Thermometer 4 is
fixed at the outer surface of the copper cup bottom inside the
shell. Heater 7 (130 Ohms) of the calorimeter is made of
manganin wire wound bifilarly onto the outer surface of the
shell and cemented with butvar-phenolic adhesive (BP-2)
for a better thermal contact between the calorimeter and the
heater. Copper wires (0.18 mm in diameter) are fixed with
BP-2 onto the inner surface of the shell. The wire ends are
electric terminals soldered to the wires of thermometer 4,
heater 7 of the calorimeter and the wires running from of
adiabatic shield 8. The mass of the calorimeter was about
0.8 g. A thin layer of the vacuum Apiezon grease was ap-
plied to the bottom of calorimeter to improve the thermal
contact between sample 5 and calorimeter 6. The calorime-
ter is suspended inside thermal shield 8 on manganin wires
running from the thermal shield to the thermometer and the
heater of the calorimeter. It is centered with Kevlar threads.
The calorimeter is cooled through the manganin wires.
Thermal shield 8 was mounted below helium bath 9 using
special thermoinsulating suspensions 21. The components of
the calorimeter are shown in Fig. 2.
Bath 9 (about 7 cm3) is connected via thin-walled stain-
less steel pipe 10 (6 mm in diameter, 100 mm long) with
adsorption pump 26 filled by absorbent carbon “SKN-1K”
(~24 cm3). The adsorption pump removes helium vapor
from the bath. Pipe 10 is soldered to cold plate 11 with a
60% Sn–40% Pb solder that allows condensing helium to
bath 9. The bath can be filled with either 4He or 3He. This
ensures the lowest temperature of the calorimeter down to ~
1 or 0.3 K, respectively. 4He was used in this investigation.
On measuring in the region below 2 K, the temperature of
the bath 9 was held constantly at ~ 1 K for about six hours.
Above 2 K the calorimeter can be cooled by pumping 4He
vapor from bath 9 or the helium bath of the cryostat. The
temperature of adsorption pump 26 was controlled with
carbon thermometer 15 and a differential copper–
constantan thermocouple placed between the cold plate and
the adsorption pump. The operation conditions of the ad-
sorption pump are controlled with heater 14 wound onto
the outer surface of heat exchanger 24.
The calorimetric cell is placed into a vacuum chamber
of an inset consisting of upper 25 and lower 3 parts. The
upper part of the inset is made of a thin-walled stainless
steel pipe. Its lower part is made of copper. There is a cold
copper plate between the upper and lower parts of the calo-
rimeter. The adiabatic calorimeter is suitable to place into a
M.I. Bagatskii, V.V. Sumarokov, and A.V. Dolbin
536 Fizika Nizkikh Temperatur, 2011, v. 37, No. 5
Fig. 1. The principal diagram of the low-temperature part of the
calorimeter: 1 — a helium cryostat (or a portable Dewar); 2 — the
helium container of cryostat; 3 — a body of the insert (lower part);
4 — the thermometer “CERNOX”; 5 — a sample; 6 — the calo-
rimeter; 7 — the calorimeter heater; 8 — the adiabatic shield; 9 —
the low-temperature chamber; 10 — a tube; 11 — a cold plate; 12,
15 — a carbon thermometer; 13 — a sorbent; 14 — the adsorber
heater; 16, 28, 29 — a valve; 17 — a pipe to 4He (3He) gas sys-
tem; 18 — a vacuum part of the insert; 19 — a differential ther-
mocouple Au + 0.03% Fe–Cu; 20 — the adiabatic shield heater;
21 — the suspension of the calorimetric cell; 22 — the low-
temperature joint; 23 — a channel for supplying by liquid 4He of
the heat exchanger of the adsorber; 24 — the heat exchanger of the
adsorber; 25 — the insert body (upper part); 26 — the adsorption
pump; 27 — the helium pumping line via the adsorber heat ex-
changer; 30 — the helium pumping line; 31 — the lead-in.
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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
28
29
30
31
4
He
4
He
Fig. 2. The details of the calorimeter (with a technological gad-
get), the adiabatic shield with the system of suspension.
helium vessel of a portable Dewar or a helium cryostat.
The part of the inset that is immersed into the helium
cryostat is 1 m long and 22 mm in outer diameter. Low-
temperature vacuum joint 22 was mounted on cold plate 11
to provide an access to the elements of the calorimetric
cell. Cold plate 11 had holes for electric leads running
from thermometer 4, thermocouple 19 and heaters 7 and 20
and channel 23 for supplying by liquid 4He of heat ex-
changer 24 of adsorption pump 26 from helium container 2
of the outside cryostat. Carbon thermometer 12 was
mounted on the upper side of the plate.
The temperature of the calorimeter is measured with a
calibrated CERNOX CX-1010-SD-0.3D resistance thermo-
meter (Lake Shore Cryotronics) connected to the measuring
circuit in a four-wire configuration. The thermometer was
fed with a precision dc voltage source with a periodically
varying polarity, which minimized the effect of parasitic emf
in the measuring circuit of the resistance thermometer.
The adiabatic conditions of the experiment (dT/dt ≤
≤ 10–3–10–4 K/min) are maintained with a special elec-
tronic system controlling the temperature of the adiabatic
shield. The system includes differential thermocouple
[Au + 0.03 at.%Fe–Cu] 19 between calorimeter 6 and
thermal shield 8, as well as thermal shield heater 20, pho-
toelectric and power amplifiers.
The calorimetric experiment was controlled with a per-
sonal computer (PC) using the data management and ac-
quisition system based on a Keithley 2700/7700 multime-
ter. The PC and the measuring system were connected
through an Advantech PC1-1671 interface board affording
the IEEE-488 (GPIB) — standard data exchange. On reach-
ing the temperature run (≤10–3–10–4 K/min) of the calorime-
ter, the Keithley 2700/7700 multimeter switches on a heater
by the operator's command and thus ensures the preassigned
heat input to the calorimeter. The characteristic variation of
the calorimeter temperature during the time of heating is
ΔТ ≈ 0.05 Т, where T is the temperature of the calorimeter.
The time of heating varied within 1–5 min. The running
time of the experiment is specified by the computer.
The specific heat of the test sample of fullerite CF is de-
scribed as follows:
[ ]2 1( ) / ( ) / ,F c fC T iU T T C m= τ − −
where i is the current through the calorimeter heater during
the time τ; U is voltage drop at the heater; T1 and T2 are the
starting and final equilibrium temperatures of calorimeter,
respectively; Cc is the heat capacity of the empty calorime-
ter; mf is the mass of the test sample; Т = T1 + (T2 – T1)/2.
A simple low-temperature adiabatic calorimeter for small samples
Fizika Nizkikh Temperatur, 2011, v. 37, No. 5 537
Fig. 3. The temperature dependence of the heat capacity of the
empty calorimeter. Experiment: open circle; solid line — a
fitting curve.
0 5 10 15 20 25 30
0
0.01
0.02
0.03
0.04
T, K
C
,
J/
K
Fig. 4. The total heat capacity Ct of the calorimeter with the sam-
ple, the heat capacities of the empty calorimeter Cc, the sample
CF and grease Apiezon CA.
0 5 10 15 20 25 30
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
T, K
C
t
C
F
C
c
C
A
C
,
J/
K
The relative error in the measurement of the heat intro-
duced to the calorimeter (iUτ) is less than 0.2% in the
whole temperature range. The main contribution to the
error of the heat capacity measurement is made by the ran-
dom and systematic errors occurring in estimation of the
difference between the calorimeter temperatures T2 – T1.
The equilibrium temperatures T1 and T2 were found by
extrapolating the time dependences of the calorimeter tem-
perature (dT/dt) measured in the equilibrium periods before
and after heating to the mid-time of heating. The above
errors in the temperature difference appear because of the
inaccuracies in considering the residual heat exchange be-
tween the calorimeter and the thermal shield.
The heat capacity of the empty calorimeter Cc was meas-
ured in a separate experiment. The experimental data of the
heat capacity of the empty calorimeter and the smoothed
curve are shown in Fig. 3. The smoothed curve was obtained
through approximation of the experimental results by the
equation C = Σ aiT
i (i = 1, ..., 9) in a nonphysical form. The
c.m.s. error is 1.3%. The deviation of the experimental data
from the smoothed curve was up to about 1% at high tem-
peratures and about 18% at the lowest temperature.
To check the operation of the calorimeter, the heat ca-
pacity of the C60 sample was measured in the temperature
interval 1–30 K. The test sample was a cylinder (≈ 6 mm
high and 10 mm in diameter). The sample was prepared in
Sweden (Umea University) by compacting a C60 powder
under the pressure 1 kbar. The characteristic sizes of the
C60 crystals were 0.1–0.3 mm. The purity of fullerite C60
was 99.99%. The masses of the C60 sample and the Apie-
zon grease were mf = (586.48 ± 0.05) mg and ma = (0.45 ±
± 0.05) mg, respectively.
Before the experiment, the fullerite sample was held at
T = 350 °C in a special device for 48 h under the condition
of dynamic evacuation. This was done to remove the gas
impurities and moisture from the sample. Weighing and
mounting the sample into the calorimeter and hermetic
sealing of the vacuum chamber took several hours. Then
the vacuum chamber of the calorimeter was “washed” sev-
eral times with pure nitrogen gas and backing pumped for
about eight hours. The residual N2 pressure in the chamber
was up to several millitorrs.
The experimental data on the total heat capacity of the
calorimeter with the sample of fullerit C60, the empty calo-
rimeter and the sample are illustrated in Fig. 4. The contri-
bution of the Apiezon grease to the total heat capacity was
accounted with using the literature data on the heat capaci-
ty of Apiezon from Ref. 1.
The contribution of the sample to the total heat capacity
of the calorimeter with the sample was 45% below 2 K,
75% at 4 K, 80% at 10 K, 70% at 20 K and 45% at 30 K.
The temperature dependence of C60 specific heat ob-
tained in this experiment is shown in Fig. 5 along with
literature data [2–4]. The error in the determination of the
specific heat of C60 is up to 20% at 2 K, 10% at 4 K and
decreases to 3% as the temperature rises to 30 K.
Note that the errors in the specific heat of C60 are not
specified in Refs. 2–4.
Atake et al. [2] used an adiabatic calorimeter to investi-
gate the heat capacity of fullerite C60 in the temperature
region 11–300 K. The C60 sample contained about 8% of
graphite and its weight (≈ 0.88 g) was much lower than
that of the calorimetric vessel (35 g). As a result, the con-
tribution of the sample to the total heat capacity was only
8% at T = 20 K. The highest discrepancy between our re-
sults and the data of Ref. 1 is 12%.
Beyermann et al. [3,4] measured the heat capacity of
C60 at T = 1.4–20 K by the thermal relaxation method. The
mass of the sample and the C60 purity are not specified in
Refs. 3, 4. Two series of measurements were made. The
M.I. Bagatskii, V.V. Sumarokov, and A.V. Dolbin
538 Fizika Nizkikh Temperatur, 2011, v. 37, No. 5
Fig. 5. The temperature dependence of the heat capacity of fulle-
rit C60: from Refs. 3, 4 (1), this work (2), from Ref. 2 (3).
0 5 10 15 20 25 30
0,00
0,02
0,04
0,06
T, K
C60
1
2
3
C
,
J/
(g
K
)
�
measurements in series II [4] were made after heating of the
sample in vacuum at 430 K. Above 3 K the discrepancy
between series I and II was no more than 16%. At T < 2 K
the results of series I were an order of magnitude higher
than those of series II. The data of Refs. 3, 4 exceeded our
results systematically by 5–12% at T = 4–20 K. As the
temperature lowers, the discrepancy between our results
and those of Refs. 3, 4 increases.
Thus, the results of this study agree quite well with lite-
rature data [2–4] in the region 4–30 K.
Conclusions
A simple adiabatic calorimeter has been made to investi-
gate the effects of gas admixtures on the heat capacity of
small samples (with diameter ≤ 10 mm, 1 cm3 by volume)
of carbon nanomaterials in the temperature range from 1 to
300 K. The design of the calorimeter makes possible:
i) short-time mounting of a test sample, which is particularly
important for investigations of both the heat capacity of pure
nanomaterials and the effects caused by gas admixtures;
ii) doping of a sample by gases directly in the calorimeter;
iii) short-time cooling of a sample down to helium tempera-
tures. The adiabatic calorimeter is suitable to place into a
helium vessel of a portable Dewar or a helium cryostat. The
heat capacity of the C60 sample has been measured in the
temperature range 1–30 K. The results of this study agree
quite well with literature data [2–4] in the region 4–30 K.
1. C.A. Swenson, Rev. Sci. Instr. 70, 2728 (1999).
2. T. Atake, T. Tanaka, H. Kawaji, K. Kikuchi, S. Saito,
S. Suzuki, I. Ikemoto, and Y. Achiba, Physica C185–189,
427 (1991).
3. W.P. Beyermann, M.F. Hundley, J.D. Thompson, F.N.
Diederich, and G. Grüner, Phys. Rev. Lett. 68, 2046 (1992).
4. W.P. Beyermann, M.F. Hundley, J.D. Thompson, F.N.
Diederich, and G. Grüner, Phys. Rev. Lett. 68, 2737 (1992).
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