2
0
2017
kny
par
0
journal
Original
Knyazev, A. V.
Paraguassu, W.
Blokhina, A. G.
Lelet, M. I.
Knyazeva, S. S.
Correa Junior, G. B.
J. Chem. Thermodyn.
2017
2020-09-29
Thermodynamic and spectroscopic properties of KNbTeO6
In the present work, the temperature dependence of heat capacity of KNbTeO6 has been measured for the first time over the range from 6 K to 332 K by precision adiabatic vacuum calorimetry. The experimental results were used to calculate standard thermodynamic functions, namely the heat capacity Cp o(T), enthalpy H (T) - H (0), entropy S (T) - S (0) and Gibbs function G (T) - H (0), for the range from T= 0 K to 332 K. The phase transitions and thermal decomposition of KNbTeO6 were determined by differential scanning calorimetry. Structural changes in phase transitions were studied by high-temperature Raman spectroscopy.
Pyrochlore
KNbTeO6
Adiabatic vacuum calorimetry
Heat capacity
Thermodynamic functions
Raman spectroscopy
10.1016/j.jct.2016.12.013
107
26-36
1
InChI=1S/K.Nb.H2O4Te.2O/c;;1-5(2,3)4;;/h;;(H2,1,2,3,4);;/q2*+1;;;/p-2
AJQQXUCCCIKARF-UHFFFAOYSA-L
niobium potassium tellurate (KNbTeO6)
KNbO6Te
1
Synthesized by the authors
1
99.5
3
Spectroscopy
1
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Triple point temperature, K
DSC
Crystal 3
Direct value, X
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 3
Crystal 2
Air at 1 atmosphere
1
1079
4
1
4
2
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Triple point temperature, K
DSC
Crystal 2
Direct value, X
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 2
Crystal 1
Air at 1 atmosphere
1
1137
4
1
4
3
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Molar heat capacity at constant pressure, J/K/mol
Vacuum adiabatic calorimetry
Crystal 3
Direct value, X
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 3
1
Pressure, kPa
Crystal 3
100
1
1
Temperature, K
Crystal 3
1
6.22
3
1
0.2151
4
1
0.0132
1
6.35
3
1
0.2384
4
1
0.0141
1
6.48
3
1
0.2615
4
1
0.0152
1
6.59
3
1
0.2896
4
1
0.0159
1
6.69
3
1
0.3201
4
1
0.017
1
6.79
3
1
0.3566
4
1
0.0184
1
6.89
3
1
0.3726
4
1
0.0191
1
6.98
3
1
0.4048
4
1
0.0202
1
7.08
3
1
0.4359
4
1
0.0214
1
7.17
3
1
0.4578
4
1
0.0222
1
7.26
3
1
0.4944
4
1
0.0236
1
7.35
3
1
0.5369
4
1
0.0252
1
7.45
3
1
0.5789
4
1
0.027
1
7.55
3
1
0.6229
4
1
0.0286
1
7.62
3
1
0.6503
4
1
0.0297
1
7.74
3
1
0.7007
4
1
0.0317
1
7.85
3
1
0.7757
4
1
0.0347
1
7.96
3
1
0.847
4
1
0.0376
1
8.08
3
1
0.9232
4
1
0.0407
1
8.2
3
1
0.9807
4
1
0.0429
1
8.32
3
1
1.069
4
1
0.046
1
8.45
3
1
1.151
4
1
0.05
1
8.58
3
1
1.212
4
1
0.052
1
8.72
3
1
1.319
4
1
0.056
1
8.87
3
1
1.439
4
1
0.061
1
9.02
3
1
1.533
4
1
0.065
1
9.18
3
1
1.649
4
1
0.07
1
9.34
3
1
1.774
4
1
0.074
1
9.51
3
1
1.875
4
1
0.078
1
9.69
3
1
2.05
4
1
0.085
1
9.85
3
1
2.16
4
1
0.09
1
10.03
4
1
2.307
4
1
0.096
1
10.3
4
1
2.508
4
1
0.104
1
10.65
4
1
2.734
4
1
0.113
1
11.01
4
1
3.057
4
1
0.125
1
11.37
4
1
3.289
4
1
0.135
1
11.73
4
1
3.568
4
1
0.146
1
12.11
4
1
3.815
4
1
0.156
1
12.48
4
1
4.075
4
1
0.166
1
12.86
4
1
4.366
4
1
0.178
1
13.24
4
1
4.629
4
1
0.188
1
13.63
4
1
4.92
4
1
0.2
1
14.03
4
1
5.184
4
1
0.21
1
14.42
4
1
5.497
4
1
0.223
1
14.82
4
1
5.813
4
1
0.236
1
15.22
4
1
6.113
4
1
0.248
1
15.62
4
1
6.465
4
1
0.262
1
16.03
4
1
6.826
4
1
0.276
1
16.44
4
1
7.129
4
1
0.288
1
16.85
4
1
7.56
4
1
0.306
1
17.26
4
1
7.878
4
1
0.318
1
17.68
4
1
8.231
4
1
0.333
1
18.1
4
1
8.697
4
1
0.351
1
18.52
4
1
9.061
4
1
0.366
1
18.94
4
1
9.437
4
1
0.381
1
19.36
4
1
9.89
4
1
0.399
1
19.79
4
1
10.29
4
1
0.41
1
20.53
4
1
11.03
4
1
0.12
1
21.58
4
1
12.05
4
1
0.13
1
22.65
4
1
13.09
4
1
0.14
1
23.73
4
1
14.14
4
1
0.15
1
24.82
4
1
15.46
4
1
0.17
1
25.38
4
1
16.01
4
1
0.17
1
26.5
4
1
17.19
4
1
0.18
1
27.62
4
1
18.26
4
1
0.19
1
28.75
4
1
19.37
4
1
0.2
1
29.88
4
1
20.42
4
1
0.21
1
31.02
4
1
21.49
4
1
0.22
1
32.16
4
1
22.5
4
1
0.23
1
33.31
4
1
23.51
4
1
0.24
1
34.46
4
1
24.54
4
1
0.25
1
35.62
4
1
25.49
4
1
0.26
1
36.78
4
1
26.48
4
1
0.27
1
37.95
4
1
27.51
4
1
0.28
1
39.12
4
1
28.47
4
1
0.29
1
40.3
4
1
29.47
4
1
0.14
1
41.47
4
1
30.43
4
1
0.14
1
42.66
4
1
31.4
4
1
0.15
1
43.86
4
1
32.55
4
1
0.15
1
45.05
4
1
33.64
4
1
0.16
1
46.24
4
1
34.8
4
1
0.16
1
47.44
4
1
35.68
4
1
0.16
1
48.63
4
1
36.81
4
1
0.17
1
49.83
4
1
37.63
4
1
0.17
1
51.03
4
1
38.63
4
1
0.18
1
52.23
4
1
39.68
4
1
0.18
1
54.02
4
1
41.26
4
1
0.19
1
56.23
4
1
43.28
4
1
0.2
1
57.59
4
1
44.52
4
1
0.2
1
58.8
4
1
45.93
4
1
0.21
1
60.02
4
1
46.97
4
1
0.21
1
61.24
4
1
47.95
4
1
0.22
1
62.46
4
1
48.95
4
1
0.22
1
63.68
4
1
50.12
4
1
0.22
1
64.9
4
1
51.23
4
1
0.23
1
66.12
4
1
52.35
4
1
0.23
1
67.35
4
1
53.36
4
1
0.24
1
68.57
4
1
54.4
4
1
0.24
1
69.8
4
1
55.35
4
1
0.25
1
71.42
4
1
56.64
4
1
0.25
1
73.44
4
1
58.06
4
1
0.26
1
75.46
4
1
59.35
4
1
0.26
1
77.03
4
1
60.53
4
1
0.27
1
78.81
4
1
61.78
4
1
0.27
1
81.12
4
1
63.52
4
1
0.28
1
85.13
4
1
66.84
4
1
0.29
1
89.13
4
1
70.13
4
1
0.31
1
93.12
4
1
73.15
4
1
0.35
1
97.11
4
1
76.22
4
1
0.36
1
101.6
4
1
79.69
4
1
0.38
1
83.12
4
1
65.23
4
1
0.29
1
87.13
4
1
68.44
4
1
0.3
1
91.13
4
1
71.63
4
1
0.35
1
95.11
4
1
74.66
4
1
0.36
1
99.1
4
1
77.67
4
1
0.37
1
104.6
4
1
81.42
4
1
0.38
1
107.6
4
1
83.56
4
1
0.39
1
110.5
4
1
85.75
4
1
0.4
1
113.5
4
1
87.86
4
1
0.41
1
116.6
4
1
89.91
4
1
0.41
1
119.6
4
1
91.91
4
1
0.42
1
122.6
4
1
93.92
4
1
0.43
1
125.6
4
1
95.85
4
1
0.44
1
128.6
4
1
97.8
4
1
0.44
1
131.6
4
1
99.73
4
1
0.45
1
134.6
4
1
101.7
4
1
0.5
1
137.6
4
1
103.4
4
1
0.5
1
140.7
4
1
105.3
4
1
0.5
1
143.7
4
1
107.1
4
1
0.5
1
146.7
4
1
108.8
4
1
0.5
1
149.8
4
1
110.7
4
1
0.5
1
152.8
4
1
112.3
4
1
0.5
1
155.8
4
1
114
4
1
0.5
1
158.9
4
1
115.6
4
1
0.5
1
161.9
4
1
117.3
4
1
0.5
1
165
4
1
119.1
4
1
0.5
1
168
4
1
120.5
4
1
0.5
1
171.1
4
1
122
4
1
0.5
1
174.1
4
1
123.5
4
1
0.5
1
177.2
4
1
125.1
4
1
0.6
1
180.2
4
1
126.6
4
1
0.6
1
183.3
4
1
128
4
1
0.6
1
186.3
4
1
129.4
4
1
0.6
1
189.3
4
1
130.8
4
1
0.6
1
192.4
4
1
132.2
4
1
0.6
1
195.4
4
1
133.4
4
1
0.6
1
198.5
4
1
134.8
4
1
0.6
1
201.5
4
1
136.1
4
1
0.6
1
204.6
4
1
137.4
4
1
0.6
1
207.6
4
1
138.5
4
1
0.6
1
210.7
4
1
139.7
4
1
0.6
1
213.8
4
1
141.1
4
1
0.6
1
216.9
4
1
142.1
4
1
0.6
1
219.9
4
1
143.4
4
1
0.6
1
223
4
1
144.5
4
1
0.6
1
226.1
4
1
145.7
4
1
0.6
1
229.1
4
1
147.1
4
1
0.6
1
232.2
4
1
148.3
4
1
0.6
1
235.2
4
1
149.4
4
1
0.6
1
238.3
4
1
150.2
4
1
0.7
1
241.4
4
1
151.3
4
1
0.7
1
244.4
4
1
152.4
4
1
0.7
1
247.5
4
1
153.2
4
1
0.7
1
250.6
4
1
154.2
4
1
0.7
1
253.6
4
1
155.1
4
1
0.7
1
256.7
4
1
156.1
4
1
0.7
1
259.7
4
1
157.1
4
1
0.7
1
262.8
4
1
158
4
1
0.7
1
265.9
4
1
158.8
4
1
0.7
1
269
4
1
159.7
4
1
0.7
1
272
4
1
160.7
4
1
0.7
1
275.1
4
1
161.6
4
1
0.7
1
278.1
4
1
162.5
4
1
0.7
1
281.1
4
1
163.2
4
1
0.7
1
284.1
4
1
164.1
4
1
0.7
1
287.2
4
1
165
4
1
0.7
1
290.2
4
1
165.7
4
1
0.7
1
293.2
4
1
166.4
4
1
0.7
1
296.2
4
1
167.2
4
1
0.7
1
299.2
4
1
168
4
1
0.7
1
302.6
4
1
169
4
1
0.7
1
307.3
4
1
170
4
1
0.7
1
312.5
4
1
171.4
4
1
0.7
1
317.7
4
1
172.5
4
1
0.7
1
322.9
4
1
173.8
4
1
0.7
1
328
4
1
174.9
4
1
0.8
1
333
4
1
176
4
1
0.8
4
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Molar heat capacity at constant pressure, J/K/mol
Vacuum adiabatic calorimetry
Crystal 3
Direct value, X
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 3
1
Pressure, kPa
Crystal 3
100
1
1
Temperature, K
Crystal 3
1
5
1
1
0.1672
4
1
0.0135
1
10
1
1
2.271
4
1
0.094
1
15
2
1
5.946
4
1
0.241
1
20
1
1
10.49
4
1
0.42
1
25
2
1
15.6
4
1
0.17
1
30
1
1
20.55
4
1
0.21
1
35
2
1
24.95
4
1
0.26
1
40
1
1
29.26
4
1
0.3
1
45
2
1
33.48
4
1
0.15
1
50
1
1
37.76
4
1
0.17
1
60
1
1
46.86
4
1
0.21
1
70
1
1
55.41
4
1
0.25
1
80
1
1
62.85
4
1
0.28
1
90
1
1
70.63
4
1
0.34
1
100
1
1
78.44
4
1
0.37
1
110
2
1
85.38
4
1
0.4
1
120
2
1
92.2
4
1
0.42
1
130
2
1
98.72
4
1
0.45
1
140
2
1
104.9
4
1
0.5
1
150
2
1
110.8
4
1
0.5
1
160
2
1
116.3
4
1
0.5
1
170
2
1
121.5
4
1
0.5
1
180
2
1
126.4
4
1
0.6
1
190
2
1
131
4
1
0.6
1
200
1
1
135.4
4
1
0.6
1
210
2
1
139.6
4
1
0.6
1
220
2
1
143.5
4
1
0.6
1
230
2
1
147.2
4
1
0.6
1
240
2
1
150.7
4
1
0.7
1
250
2
1
154
4
1
0.7
1
260
2
1
157.2
4
1
0.7
1
270
2
1
160.1
4
1
0.7
1
273.15
5
1
161
4
1
0.7
1
280
2
1
162.9
4
1
0.7
1
290
2
1
165.6
4
1
0.7
1
298.15
5
1
167.7
4
1
0.7
1
300
1
1
168.2
4
1
0.7
1
310
2
1
170.7
4
1
0.7
1
320
2
1
173.1
4
1
0.7
1
330
2
1
175.4
4
1
0.8
1
332
3
1
175.8
4
1
0.8
5
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Molar enthalpy, kJ/mol
Vacuum adiabatic calorimetry
Crystal 3
Difference with the reference state, X-X(REF)
Reference phase with the same composition at fixed temperature and pressure
0
1
100
1
Crystal 3
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 3
1
Pressure, kPa
Crystal 3
100
1
1
Temperature, K
Crystal 3
1
5
1
1
0.0004
2
1
5e-05
1
10
1
1
0.0046
2
1
0.0002
1
15
2
1
0.0251
3
1
0.001
1
20
1
1
0.0658
3
1
0.0027
1
25
2
1
0.131
3
1
0.005
1
30
1
1
0.221
3
1
0.009
1
35
2
1
0.335
3
1
0.014
1
40
1
1
0.471
3
1
0.019
1
45
2
1
0.628
3
1
0.007
1
50
1
1
0.806
3
1
0.009
1
60
1
1
1.229
4
1
0.013
1
70
1
1
1.741
4
1
0.018
1
80
1
1
2.333
4
1
0.024
1
90
1
1
2.999
4
1
0.019
1
100
1
1
3.746
4
1
0.023
1
110
2
1
4.564
4
1
0.026
1
120
2
1
5.452
4
1
0.03
1
130
2
1
6.407
4
1
0.034
1
140
2
1
7.425
4
1
0.039
1
150
2
1
8.504
4
1
0.044
1
160
2
1
9.64
4
1
0.049
1
170
2
1
10.83
4
1
0.05
1
180
2
1
12.07
4
1
0.06
1
190
2
1
13.36
4
1
0.06
1
200
1
1
14.69
4
1
0.07
1
210
2
1
16.06
4
1
0.08
1
220
2
1
17.48
4
1
0.08
1
230
2
1
18.93
4
1
0.09
1
240
2
1
20.42
4
1
0.1
1
250
2
1
21.95
4
1
0.1
1
260
2
1
23.5
4
1
0.11
1
270
2
1
25.09
4
1
0.12
1
273.15
5
1
25.6
4
1
0.12
1
280
2
1
26.71
4
1
0.12
1
290
2
1
28.35
4
1
0.13
1
298.15
5
1
29.71
4
1
0.13
1
300
1
1
30.02
4
1
0.14
1
310
2
1
31.71
4
1
0.14
1
320
2
1
33.43
4
1
0.15
1
330
2
1
35.17
4
1
0.16
1
332
3
1
35.53
4
1
0.16
6
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Molar entropy, J/K/mol
Vacuum adiabatic calorimetry
Crystal 3
Difference with the reference state, X-X(REF)
Reference phase with the same composition at fixed temperature and pressure
0
1
100
1
Crystal 3
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 3
1
Pressure, kPa
Crystal 3
100
1
1
Temperature, K
Crystal 3
1
5
1
1
0.1338
4
1
0.0145
1
10
1
1
0.6247
4
1
0.0409
1
15
2
1
2.241
4
1
0.137
1
20
1
1
4.553
4
1
0.276
1
25
2
1
7.431
4
1
0.448
1
30
1
1
10.73
4
1
0.65
1
35
2
1
14.23
4
1
0.86
1
40
1
1
17.84
4
1
1.07
1
45
2
1
21.53
4
1
0.34
1
50
1
1
25.28
4
1
0.39
1
60
1
1
32.96
4
1
0.51
1
70
1
1
40.84
4
1
0.63
1
80
1
1
48.73
4
1
0.75
1
90
1
1
56.58
4
1
0.44
1
100
1
1
64.43
4
1
0.48
1
110
2
1
72.23
4
1
0.52
1
120
2
1
79.95
4
1
0.56
1
130
2
1
87.59
4
1
0.61
1
140
2
1
95.13
4
1
0.65
1
150
2
1
102.6
4
1
0.7
1
160
2
1
109.9
4
1
0.7
1
170
2
1
117.1
4
1
0.8
1
180
2
1
124.2
4
1
0.8
1
190
2
1
131.2
4
1
0.9
1
200
1
1
138
4
1
0.9
1
210
2
1
144.7
4
1
0.9
1
220
2
1
151.3
4
1
1
1
230
2
1
157.7
4
1
1
1
240
2
1
164.1
4
1
1.1
1
250
2
1
170.3
4
1
1.1
1
260
2
1
176.4
4
1
1.1
1
270
2
1
182.4
4
1
1.2
1
273.15
5
1
184.3
4
1
1.2
1
280
2
1
188.3
4
1
1.2
1
290
2
1
194
4
1
1.2
1
298.15
5
1
198.7
4
1
1.3
1
300
1
1
199.7
4
1
1.3
1
310
2
1
205.2
4
1
1.3
1
320
2
1
210.7
4
1
1.3
1
330
2
1
216.1
4
1
1.4
1
332
3
1
217.1
4
1
1.4
7
1
1
Principal objective of the work
AB
TRC
8/14/2017
1
Mass density, kg/m3
X-ray diffraction
Crystal 3
Direct value, X
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Crystal 3
1
Pressure, kPa
Crystal 3
101.325
6
1
Temperature, K
Crystal 3
1
298
3
1
4406
4
1
4
1
373
3
1
4405
4
1
4
1
473
3
1
4401
4
1
4
1
573
3
1
4394
4
1
4
1
673
3
1
4387
4
1
4
1
773
3
1
4379
4
1
4
1
873
3
1
4368
4
1
4