Crystal Growth Activity

Objective:

The growth of novel and technologically important materials, especially in the form of single crystals, serves as the foundation stone for the scientific and technological developments of the human civilization. High-quality single crystals are an integral part of many new and existing technologies. Single crystals play a crucial role in this regard and are often required to achieve a material’s full functionality, as well as to completely describe its properties. Hence, over the years the growth and characterization of technologically important crystals have evolved as a thrust area in materials- science research.

There are different techniques employed for the growth of single crystals. Some of the important growth techniques are given below:




At LFMD several single crystals for laser-host, non-linear optical, ferroelectric and detector applications are grown using different growth techniques. Also crystal growth workstations with precision controls and high temperature stability have been designed and developed in-house. The grown crystals are characterised using characterization facilities available in the Division such as XRD, FTIR, DSC, TG-DTA, polarizing light microscope, optical interferometers, thermo-luminescence set up, hysteresis loop tracer, impedance analyzer etc. Several devices have been fabricated using the grown crystals.

Click below for further information:

Non-linear optical crystals

Highlights:

  • Several non-linear optical crystals like Potassium di-hydrogen phosphate (KDP), Deuterated potassium dihydrogen phosphate (DKDP), stochiometric and congruent lithium niobate (LN) and lithium tantalate (LT), Potassium titanyl phosphate (KTP), borates etc. are grown by solution and melt growth techniques.
  • These crystal are grown for harmonic generation of laser output, electro-optic modulation applications.
  • KDP crystal of size 116 x 92 x 116 mm3 weighing 2.6 kg has been grown.
  • Large diameter lithium niobate (dia. 70 mm) and lithium tantalate (dia. 50 mm) crystals have been grown.
  • Several innovations like Mercury Seal Technique (to process solution with immersed seed), Flat-top Technique (to increase usable volume), Nucleation-trap Crystallizer (to trap spurious nucleation) for the growth of good quality crystals have been conceptualized and implemented.
  • Several SHG elements and Electro-optic modulators have been fabricated and tested.


Laser crystals

Highlights:

  • Several rare earth doped ortho-vanadate crystals have been grown for application as laser gain medium.
  • Cr co-doped rare earth vanadates are grown for self Q-switching application.

1. Crystals grown by Optical Floating Zone Technique

Piezoelectric and ferroelectric crystals

Highlights:

  • Several lead-based and lead free ferroelectric crystals have been grown and investigated.

1. Crystals grown by Optical Floating Zone Technique


2. Crystals grown by high temperature slution growth Technique

Crystals for other applications

1. Crystals grown by low temperature solution growth.


2. Crystals grown by Czochralski method.


3. Crystals grown by Optical Floating Zone Technique.

Investigations on single crystals

1. investigations on piezoelectric crystals


2. Investigations on undoped and doped Gallium oxide crystal


3. Unusual absorption and emission characteristics of Cr co−doped Nd:GdVO4 laser gain crystal


4. Investigation of optical and spectroscopic properties of Nd co-doped Yb:YVO4 single crystals


5. Spectroscopic properties and Judd-Ofelt analysis of Nd doped GdVO4 single crystals


6. Effect of oxygen partial pressure on the oxidation state of chromium in Nd:Cr:YVO4 single crystals


7. Bipolar electro-caloric effect (ECE) in SrxBa(1−x)Nb2O6 lead-free ferroelectric single crystal

Innovations for crystal growth techniques

  • Several innovations like Mercury Seal Technique (to process solution with immersed seed), Flat-top Technique (to increase usable volume), Nucleation-trap Crystallizer (to trap spurious nucleation) for the growth of good quality crystals have been conceptualized and implemented.
  • A novel seeding technique has been developed which helps in the quick establishment of the growth temperature with minimum wastage of seed.

1. Mercury seal technique (to process solution with immersed seed)


2. Flat-top technique (to increase usable volume)


3. Nucleation-trap crystallizer (to trap spurious nucleation)


4. Novel seeding technique