Examples of artificially grown crystals

lanthanum praseodymium aluminate 

Grown by OFZ in reducing conditions. The Brown region is indicative of Pr4+, where the desired green region is indicative of Pr3+. The quick transition from brown to green at the necked region occurred as a result of a bubble popping in the zone during growth.
[Contributed by Chapin Korosec on 30 Jul 2014]          

Crystal details

Compound name lanthanum praseodymium aluminate
Formula La0.8Pr0.2AlO3
Dimensions 4x4x60mm
Mass 4.6g
Colour transparent, green, brown
Keywords inorg; oxide; bulk

Growth conditions

Technique Optical Floating Zone
Temperature 2300 K
Growth rate
Doping procedure
Keywords melt; sol; solid


Application(s) This perovskite exhibits various structural phase transitions as well as Jahn-teller distortions. The temperature of the transitions is dependent on x in La(1-x)Pr(x)AlO3. The structure is found to go from (from high to low in temperature) Pm3m to R3c to C2/m. Study of these phase transitions is still being conducted. Recently, heat capacity measurements were taken for the transition R3c to C2/m where no latent heat was found. Further studies are planned with these large single crystals to understand the complex structural change.
Link(s) http://pubs.acs.org/doi/abs/10.1021/cg101273y; http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.174106
Other remarks

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