|
| |
FIZIKA A 9 (2000) 1 , 9-26
 
SHAPE RELAXATION DURING EQUILIBRIUM-LIKE GROWTH OF SPHERICAL CUPROUS
SELENIDE SINGLE CRYSTALS
ZLATKO VUČIĆ and JADRANKO GLADIĆ
Institute of Physics, Bijeni cka c. 46, P.O.Box 304, HR-10000,
Zagreb, Croatia
E-mail addresses: vucic@ifs.hr, gladic@ifs.hr
Dedicated to Professor Boran Leontić on the occasion of his 70th
birthday
Received 22 November 1999; revised manuscript received 8 May 2000
Accepted 5 June 2000
The spherical equilibrium-like shaped single crystals of nonstoichiometric cuprous
selenide have been grown using the modified Ohachi's method at about 30 K below its
roughening temperature, TR(111) » 830 K. The
growth has been performed under conditions of a constant volume growth rate. During the
growth of partly faceted ((111) facets) and partly rounded crystal, the sphere diameter,
the diameters of the facets and the heights of the facets were measured in situ, using a
CCD camera. Two growth features have been observed. First, there is the exponential-like
shape relaxation toward its equilibrium form with a single relaxation time constant of
about 1200 minutes, and second, there are facet size oscillations with the period of about
100 minutes, superimposed on the shape relaxation. The facet size oscillations accompanied
by facet height time stepping appear to be the basic feature of the growth of faceted
crystals of a nearly equilibrium shape. The oscillations feature, being probably the
consequence of the facet pinning potential, seems to have certain similarity with the
recently reported stepping-like growth mode of 4He solid/liquid interface at 2
mK.
PACS numbers: 66.30Dn; 81.10.-h; 81.10.Aj
UDC 538.911, 531.364.6
Keywords: cuprous selenide, nearly equilibrium spherical shape, Ohachi's method, facet
size oscillations, stepping-like growth mode
|
