Type III KG
d(PO
3)
4 (KGP) an
d KN
d(PO
3)
4 (KNP) inclusion-free single crystals can be grown using the top see
de
dsolution growth-slow cooling metho
d without pulling even though the viscosity of the solution is high (aroun
d 16 Pa·s
-1 near thecrystallization temperature). Poisoning by impurities in the crystals was minimize
d by using the correspon
ding self-fluxes as solvent.We
determine
d their main growth process by analyzing the typical micromorphologies that appeare
d on the surface of the as-grownfaces. The crystal morphologies of KGP an
d KNP were i
dentifie
d using X-ray
diffraction analysis. The external habit of the crystalsappeare
d to be more symmetrical than it structurally was because, although KGP an
d KNP are monoclinic with space group
P2
1,they have an almost cubic cell because their cell parameters are similar an
d the
ddle"> angle is very close to 90
deg.gif">. We checke
d thechemical stability of KGP an
d KNP in basic an
d aci
d me
dia. The
distribution an
d geometry of structural
defects were stu
die
d byanalyzing the etch pits that appeare
d on the {100}, the {010}, an
d the {001} forms. The crystals cleave
d parallel to {010} an
d{001}, so the surface micromorphology of both forms was stu
die
d. We
determine
d the orientation, the
density, an
d the height of thecleave
d planes. We also characterize
d the local plastic
deformation of KGP an
d KNP by measuring the microhar
dness on the {100},{010}, an
d {001} forms using an in
dentation metho
d.