A close up image of crystals forming under a microscope, performed on a Syrris Atlas HD Crystallization system

What is crystallization?

Discover a detailed explanation of crystallization, its uses in industry, and the various methods and technology available for performing it.


The crystallization process - crystal growth rate vs. nucleation rate - Syrris
Figure 1: The crystallization process - crystal growth rate vs. nucleation rate
Crystallization - Solubility Curves, Supersaturation and the Metastable Zone Width (MSZW) - Syrris
Figure 2: A solubility and temperature graph for various solvents
crystallization solubility curve
Crystallization solubility curve
Nucleation, growth rate, and crystal size
Nucleation, growth rate, and crystal size
The Sonocrystallization Process - compression and rarefaction - Syrris
The sonocrystallization process - compression and rarefaction
Onset of Nucleation and Dissolution Graph in the sonocrystallization process - Syrris
Onset of nucleation and dissolution graph in the sonocrystallization process
Example solubility curve: Crystallization of Adipic Acid
Example solubility curve: Crystallization of Adipic Acid
Example solubility curve: Dissolution of Adipic Acid
Example solubility curve: Dissolution of Adipic Acid
  • Other methods of crystallization monitoring

    A number of alternative probes are also available for crystallization monitoring that provide additional information, such as “chord length” (a fundamental measurement related to particle size), and concentration of solute in the mother liquor or crystal shape/distribution.


    FBRM probes work by directing a laser beam down the probe, through rotating optics and focussing it at the probe window and measuring the light backscattered by particles in solution.

    As the focussed beam scans the solution, individual particles can backscatter the light to the detector. Each pulse of backscattered light is detected and it’s intensity measured. Multiplying the duration of each pulse provides the distance across each particle, known as “chord length”.

    Video Imaging

    Video imaging probes have also been used determine crystal shape and crystal size distribution, however, at present, they are hard to implement at a commercial scale due to operating temperature limits and the bulky size of such probes.


    Attenuated total reflectance Fourier transform infrared (ATR-FTIR) has also been used to gather solubility and supersaturation data, by measuring the concentration of solute in the mother liquor. Additional information can also be gleaned, such as confirmation of the presence of additives or impurities.

  • What technology is available to help chemists perform crystallization monitoring and control?

    Chemists have a range of tools available to them for performing, monitoring, and controlling crystallization chemistry. Syrris systems offer a range of solutions to the problem of crystallization monitoring and control.

    Crystallization monitoring and control with Atlas HD Crystallization

    Atlas HD Crystallization is an intelligent and automated jacketed reactor system that offers a turbidity probe for monitoring the crystallization process, and the innovative SonoLab module to perform sonocrystallization or sonomilling techniques. The system can also integrate a Lasentec FBRM probe for particle size analysis.

    Using the Syrris Atlas HD Crystallization system for your crystallization studies offers various benefits, including;

    • Fully automated synthesis – Intelligent solvent additions and temperature control are made easy with the Atlas Software allowing easy meta-stable zone analysis
    • Sonocrystallization – crystallization with narrow particle size distribution and polymorph control – See the Sonocrystallisation Applications page or the Atlas HD Sonolab system
    • Excellent temperature control using sophisticated PID temperature control
    • Extremely narrow particle distribution, improved polymorph selectivity, and complete control of nucleation