Thermal conductivity of CdCr${}_2$Se${}_4$ ferromagnet at low temperatures: role of grain boundaries and porosity

Jiří Hejtmánek, Kyo-Hoon Ahn, Zdeněk Jirák +5

It is unambiguously demonstrated that the low temperature magnon specific heat in a ferromagnet varies as T${}^{3/2}$ and the magnon thermal conductivity, due to T${}^{1/2}$ - dependen…