ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
The heat capacity of crystalline N-methylurea has been measured in the range from 223–303 K by differential scanning calorimetry, and was found to obey the relationship Cp(T)=(5.44±0.04) ×10−3 T−(0.02821±0.0016) J g−1 K−1. Thermal expansion data have also been measured in the range from 100–353 K, allowing the temperature dependent density to be calculated. From these data, the principal thermal expansion coefficients were found to vary linearly, e.g., over the range from 100–250 K. In this range α1=−(5.84±0.42)×10−5 K−1 and α2 and α3 were found to be (1.31±0.14)×10−4 K−1 and (1.04±0.10)×10−4 K−1, respectively. The thermal conductivity tensor of this orthorhombic crystal was then calculated from values of the thermal diffusivity in the directions normal to the (100), (010), and (001) planes determined by the laser flash method. The thermal conductivity coefficients at 295 K were found to be k1=0.47 W m−1 K−1, k2=0.26 W m−1 K−1, and k3=0.30 W m−1 K−1. © 1995 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.359994
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