# LOW-TEMPERATURE HEAT CAPACITIES OF POTASSIUM, RUBIDIUM, AND CESIUM

## Abstract

The heat capacities of potassium, rubidium, and cesium were measured between 0.2 and 4.2 deg K. The thermal effective mass ratios are 1.25, 1.26, and 1.43, respectively. For potassium and rubidium these quantities are in reasonable agreement with theoretical estimates of the effects of band structure, electron-electron interactions, and electron-phonon interaction. The trends of the calculated and measured values suggest that the energy-band calculations overestimate the distortion of the Fermi surface in cesium. For potassium the elastic constants are known and can be compared with the observed T/sup 3/ term in the lattice heat capacity. The agreement is within the expected experimental errors. The T/sup 5/ term, however, does not agree with calculations based on a model that includes only first- and second-neighbor interactions. (auth)

- Authors:

- Publication Date:

- Research Org.:
- Univ. of California, Berkeley

- OSTI Identifier:
- 4112014

- Report Number(s):
- UCRL-8990(Rev.)

Journal ID: PHRVA; 0031-899X

- NSA Number:
- NSA-18-010563

- Resource Type:
- Journal Article

- Journal Name:
- Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

- Additional Journal Information:
- Journal Volume: Vol: 133; Other Information: UCRL-8990(Rev.). Orig. Receipt Date: 31-DEC-64

- Country of Publication:
- United States

- Language:
- English

- Subject:
- METALS, CERAMICS, AND OTHER MATERIALS; CESIUM; ELASTICITY; ELECTRONS; ENERGY LEVELS; ERRORS; FERMI GAS; FERMI LEVEL; FERMIONS; INTERACTIONS; LATTICES; LOW TEMPERATURE; MEASURED VALUES; NUMERICALS; PHONONS; POTASSIUM; RUBIDIUM; SPECIFIC HEAT

### Citation Formats

```
Lien, W H, and Phillips, N E.
```*LOW-TEMPERATURE HEAT CAPACITIES OF POTASSIUM, RUBIDIUM, AND CESIUM*. United States: N. p., 1964.
Web. doi:10.1103/PhysRev.133.A1370.

```
Lien, W H, & Phillips, N E.
```*LOW-TEMPERATURE HEAT CAPACITIES OF POTASSIUM, RUBIDIUM, AND CESIUM*. United States. doi:10.1103/PhysRev.133.A1370.

```
Lien, W H, and Phillips, N E. Sun .
"LOW-TEMPERATURE HEAT CAPACITIES OF POTASSIUM, RUBIDIUM, AND CESIUM". United States. doi:10.1103/PhysRev.133.A1370.
```

```
@article{osti_4112014,
```

title = {LOW-TEMPERATURE HEAT CAPACITIES OF POTASSIUM, RUBIDIUM, AND CESIUM},

author = {Lien, W H and Phillips, N E},

abstractNote = {The heat capacities of potassium, rubidium, and cesium were measured between 0.2 and 4.2 deg K. The thermal effective mass ratios are 1.25, 1.26, and 1.43, respectively. For potassium and rubidium these quantities are in reasonable agreement with theoretical estimates of the effects of band structure, electron-electron interactions, and electron-phonon interaction. The trends of the calculated and measured values suggest that the energy-band calculations overestimate the distortion of the Fermi surface in cesium. For potassium the elastic constants are known and can be compared with the observed T/sup 3/ term in the lattice heat capacity. The agreement is within the expected experimental errors. The T/sup 5/ term, however, does not agree with calculations based on a model that includes only first- and second-neighbor interactions. (auth)},

doi = {10.1103/PhysRev.133.A1370},

journal = {Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D},

number = ,

volume = Vol: 133,

place = {United States},

year = {1964},

month = {3}

}