Phase-field mobility for crystal growth rates in undercooled silicates, SiO
and GeO
liquids
Kawaguchi, Munemichi
; Uno, Masayoshi*
Phase-field mobility,
, and crystal growth rates in crystallization of 11 oxides or mixed oxides in undercooled silicates, SiO
and GeO
liquids were calculated with a simple phase-field model (PFM), and material dependence of the
was discussed. Ratios between experimental crystal growth rates and the PFM simulation with
were confirmed to be proportional to a power of
on the solid/liquid interface process during the crystal growth in a log-log plot. We determined that parameters,
and
, of the
were
to
m
J
s
and
to
, which were unique for the materials. It was confirmed that our PFM simulation with the determined
reproduced quantitively the experimental crystal growth rates. The
has a proportional relationship with the diffusion coefficient of a cation molar mass average per unit an oxygen molar mass at
in a log-log graph. The
depends on the sum of the cation molar mass per the oxygen molar mass,
, in a compound. In
, the
decreases with the cation molar mass increasing. The assumed cause is that the B represents the degree of the temperature dependence of the
. Since the cation molar mass is proportional to an inertial resistance of the cation transfer, the
decreases with inverse of the cation molar mass. In crystallization of the silicates of heavy cation in
, the
saturates at approximately 0.67, which leads to
.