pressureless (viz., at around 1 atm. of gas pressure) sintering
PSD
particle size distribution
PT
ceramic with composition located in the PbO–TiO2 system
PVDF
polyvinylidene fluoride
PW
power [W]
PZT
ceramic with composition located in the PbO–ZrO2–TiO2 system; main source of piezoceramics
R
gas constant
R
reflectance
RE +
rare-Earth cation
RIT
real in-line transmission
RT
room temperature
RTP
ready-to-press powder
S
scattered fraction of incident EMR beam intensity
SEM
scanning electron microscope
SIMS
secondary ions mass spectroscopy
SOX
solid oxides
SPS
spark-plasma sintering
STEM
scanning TEM
t
tetragonal
ta0
post-sintering annealing (mostly in air) temperature
tf
melting (fusion) temperature
tg
glass transition temperature
tl
liquidus temperature (phase diagrams)
ts0
sintering temperature
T
transmittance (T% transmission percentage)
T%
transmission (in %) as a function of wavelength
TC
transparent ceramic
TD or ρ
theoretical density [g/cm3]
TEM
transmission mode electron microscope
TEOS
tetra-ethyl-ortho-silicate
TFT
total forward transmission
TGC
transparent glass-ceramic
TGG
Terbium, Gadolinium garnet
TM+
transition element cation
TRS
transversal rupture strength
T-YAG (or other
transparent YAG
transparent ceramic
compound)
TZP
tetragonal zirconia polycrystals
UV
ultraviolet domain of the spectrum (10 to ∼380 nm)
VIS
segment of the electromagnetic radiation spectrum to which the human eye is sensitive (∼0.38 to ∼0.75 μm)
VS
sintering under vacuum
WLED
white light emitting LED
X
powder particle size
XRD
X-ray diffraction
YAG
Yttrium, Aluminum garnet
YSAG
scandium containing
[K−1]
thermal expansion coefficient [°C/K]
γ
surface tension [N/m]
Δ
small variation
ε
extinction coeff. [l/(mol cm)]
λ
wavelength [nm, μm]
λth
thermal conductivity [W/Km]
ν
frequency [Hz]
ν-
wave number [cm−1]
τ
time
φ
phase of wave
1 Introduction
1.1 Importance of Transparent Ceramics: The Book's Rationale Topic and Aims
Ceramics constitute a relatively new family of optical materials belonging to a larger class of transparent solids; other members of this class are glasses, single crystals, and some organic polymers [G21].
