Schematic diagram of aerodynamic levitator. A high speed video camera and pyrometer were used to measure solidification and temperature on sample surface.
Temperature-time profile recorded during undercooling and solidification of RAlO3 samples. Snap shots taken using high speed video camera clearly show formation of glass and crystalline phase. (a) NdAlO3 glass and (b) GdAlO3 crystal.
Typical cooling curves of rapidly solidified RAlO3 samples recorded using single color pyrometer at 120 Hz. Arrows indicate nucleation (T N) and post-recalescence (T P) temperatures.
In situ solidification behavior of RAlO3 samples (R = Gd, Y, Ho, Er, and Lu) captured using color high-speed video camera at 1 kHz. Frames taken at 1 ms and elapsed time indicated at top left of photograph.
RAlO3 glass (R = La–Sm) and crystalline samples (R = Eu–Lu and Y) formed directly from undercooled melt. Open and filled circles indicate vitrification and crystallization, respectively. Inset shows spherical La, Nd, and Sm glasses approximately 2.5 mm in diameter.
(a) Thermal stability of RAlO3 (R = La, Nd, and Sm) glasses measured by differential scanning calorimetry. Filled squares and circles represent glass transition temperature, T g, and crystallization onset temperature, T x, respectively. (b) T g and T x as a function of ionic radius of rare-earth elements and (c) temperature difference, ΔT (= T x − T g) of RAlO3 glass (filled triangle).
Refractive index of RAlO3 (La, Nd, and Sm) glasses at 589 nm.
Transmittance spectrum of RAlO3 glass in UV-visible region. Apparent peaks at 460 and 630 nm are irrelevant signals in spectral calibration.
(a) Densities and (b) molar volumes of RAlO3 glasses (R = La, Nd, and Sm) as a function of rare-earth element ionic radius.
X-ray diffraction spectra of as-solidified RAlO3 samples (R = Gd, Y, Ho, Er, and Lu) measured over 2θ range of 5°–80° with step width of 0.02°.
Cross-sectional scanning electron microscopy microstructure images of as-solidified RAlO3 samples (R = Gd, Y, Ho, and Lu).
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