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In this chapter, data of thermal conductivity (κ) and integrated conductivity (I*) are presented in the form of tables. Data are divided into three categories. 1. Very low temperature data (100 mK–2 K), 2. Low temperature data (4–300 K), 3. Data about crystalline materials for which a fit in a limited range of temperature is proposed.

In this chapter useful tables containing data of thermal contraction below room temperature of several materials, most of them used in cryogenic applications, are reported together with the coefficient of thermal expansion at 293 K. The values of thermal contraction are referred at the length of the sample at 293 K.

The methods to measure the thermal conductivity at low temperature are described: the steady-state techniques, (Sect. 2.2); the 3ω technique (Sect. 2.3); and the thermal diffusivity measurement (Sect. 2.4). Each of these techniques has its own advantages as well as its inherent limitations, with some techniques more appropriate to specific sample geometry, such as the 3ω technique for thin films which is discussed in detail in Sect. 2.4.2. The radial flux method is reported in Sect. 2.2.4, the laser flash diffusivity method in Sect. 2.4.1 and the “pulsed power or Maldonado technique” in Sect. 2.3.2.

Thermal expansion measurements in the high temperature range have been thoroughly explored, and various experimental methods are available even as commercial instrumentation, measurements at cryogenic temperatures have been confined to the field of high-precision laboratory experiments, needing large experimental efforts and expenses, and often also suffering from intrinsic limitations. All techniques used for the measurements of thermal expansion can be divided into two categories, namely: absolute methods and relative methods. While in the former the linear changes of dimension of the sample are directly measured at various temperature, in the latter the coefficient of thermal expansion is determined through comparison with a reference materials of known thermal expansion. A lot of experimental set-ups are described in Sect. 2.1, while Sect. 2.2 some examples of measurements performed at very low temperatures are listed.

In this chapter experimental data for materials of common use in cryogenics are reported, in particular, approximate integrated data useful for a rough estimation of the power necessary to cool down a system. Specific heat data are divided into two groups of tables: (1) very-low temperature data of c p (below about 4 K) given by a fit when possible (Sect. 3.2). (2) low temperature of c p (approximately 4–300 K) of specific heat c p and H*(integral of c p ) (Sect. 3.3).

This chapter is devoted to the description of calorimetric techniques used to measure heat capacity of solids: pulse heat calorimetry (Sect. 2.3), relaxation calorimetry (Sect. 2.4), dual slope calorimetry (Sect. 2.5), a.c. calorimetry (Sect. 2.6), differential scanning calorimetry (Sect. 2.7). Examples of measurements of heat capacity are reported in Sects. 2.3 and 2.4.

After a Sect. 1.1 devoted to electrical conductivity and a section that deals with magnetic and dielectric losses ( 1.2), this chapter explores the theory of thermal conduction in solids. The examined categories of solids are: metals Sect. 1.3.2, Dielectrics Sects. 1.3.3 and 1.3.4 and Nanocomposites Sect. 1.3.5. In Sect. 1.3.6 the problem of thermal and electrical contact between materials is considered because contact resistance occurring at conductor joints in magnets or other high power applications can lead to undesirable electrical losses. At low temperature, thermal contact is also critical in the mounting of temperature sensors, where bad contacts can lead to erroneous results, in particular when superconductivity phenomena are involved.