  We measured the mechanical loss of a dielectric multilayer reflective coating
(ion-beam-sputtered SiO2 and Ta2O5) with and without TiO2 on sapphire disks
between 6 and 77 K. The measured loss angle exhibited a temperature dependence,
and the local maximum was found at approximately 20 K. This maximum was
7.0*10^(-4) (with TiO2) and 7.7*10^(-4) (without TiO2), although the previous
measurement for the coating on sapphire disks showed almost no temperature
dependence (Phys. Rev. D 74 022002 (2006)). We evaluated the coating thermal
noise in KAGRA and discussed future investigation strategies.
