Yoichi Sato, Takunori Taira, Tomohisa Takemasa
Thermal conductivity ( κ ) of Y 2 O 3 ceramics, Y 3 Al 5 O 12 (YAG) ceramics, Y 3 Sc 2 Al 3 O 12 (YSAG) ceramics, Y 3 Ga 2 Al 3 O 12 (YGAG) ceramics, and sapphire compared to YAG single crystal from 160 K to 773 K was studied. κ of undoped Y 2 O 3 ceramics, undoped YAG single crystal, 1at.% YAG single crystal, undoped YAG ceramics, 1at.% Nd:YAG ceramics, 1at.% Nd:YSAG ceramics, 1at.% Nd:YGAG ceramics, a-cut sapphire, and c-cut sapphire at 298 K were 10.7 W/mK, 10.4 W/mK, 9.85 W/mK, 9.75 W/mK, 9.28 W/mK, 6.41 W/mK, 6.74 W/mK, 33.8 W/mK, and 35.9 W/mK, respectively. κ of Y 2 O 3 ceramics was found to be inferior to YAG single crystal below 252 K. We also investigated the linear thermal expansion coefficient ( α ) of YSAG and sapphire compared to YAG. α of 1at.% YAG ceramics, 1at.% Nd:YSAG ceramics, sapphire along a-axis, and sapphire along c-axis were 6.18×10 −6 /K, 6.46×10 −6 /K, 5.00×10 −6 /K, and 5.79×10 −6 /K, respectively.