Specific heat of some Li-compounds

Abstract

The specific heat at constant pressure of the Li(17)Pb(83) eutectic alloy, and of LiPb, Pb, γ-LiAlO 2, Li 2SiO 3 and Li 4SiO 4 has been determined up to 1000 K. The data follow the relationships: 300 ≤ T ≤ 600 c p ( Pb) = 0.119 + 3.67 × 10 −5 T solid, 600 ≤ T ≤ 800 K c p ( Pb) = 0.162−2.42 × 10 −5 T liquid, 300 ≤ T ≤ 508 K c p Li(17) Pb(83) = −0.02417 + 3.927 × 10 −4 T + 4987/ T 2 solid, 508 ≤ T ≤ 800 K c p Li(17) Pb(83) = 0.1950−9.125 × 10 −6 T liquid, 300 ≤ T ≤ 508 K c p ( LiPb) ≈ −0.04 + 8.5 × 10 −4 T solid, 300 ≤ T ≤ 1000 K c p ( γ- LiAlO 2) = 1.375 + 2.278 × 10 −4 T −39405/ T 2, 300 ≤ T ≤ 1000 K c p ( Li 2 SiO 3) = 1.504 + 2.803 × 10 −4 T −44700/ T 2, 300 ≤ T ≤ 900 K c p ( Li 4 SiO 4) = 0.775 + 16.31 × 10 −4 T + 9000/ T 2, [ c p ] = J/ g K; [ T] = K. The transition temperature for Li 4SiO 4 was measured as 945 K (onset-temperature). The transition itself seems to be a λ-transition.