Thermal expansion measurements of the Y6(Mn1 - xFex)23 compounds were carried out in the wide temperature region from 4 up to 900 K. In the paramagnetic range a considerable enhancement of the thermal expansion coefficient α has been found for the Mn-rich compounds. In Y6Mn23 α attains 40 × 10-6 K-1 and decreases nonlinearly towards 20 × 10-6 K-1 for Y6Fe23. It is assumed that this strongly enhanced value of a in the Mn-rich compounds is caused by a large spin fluctuation contribution to the total thermal expansion.
- Spin fluctuations
- Thermal expansion