BGO – Bismuth Germanate

BGOIn addition to being an electo-optic crystal used in non-linear optical applications, Bismuth Germanate is widely used for scintillation.

BGO has high atomic number and density values, with detectors using this material being lighter and smaller than others based on alkali halide scintillating material.

Bismuth Germanate offers ruggedness with non-hygroscopic material and no cleavage. With its high Z value BGO crystals are suitable for natural radioactivity detection high energy-energy physics and in Compton-scatter suppression spectrometers.

BGO’s qualities make it ideal for scintillation applications from geophysics and medicine, to high-energy and space applications.

Density [g/cm³] 7.13
Melting point [K] 1323
Thermal expansion coefficient [K-¹] 7 x 10-⁶
Cleavage plane none
Hardness (Mho) 5
Hygroscopic No
Wavelength of emission maximum [nm] 480
Lower wavelength cutoff [nm] 320
Refractive index at emission maximum 2.15
Primary decay time [µs] 300
Light yield [photons/MeV γ] 8 - 10
Photoelectron yield [% of NaI(Tl)] (y rays) 45
Temperature response -1.2%/C
Neutron capture cross-section 1.47b
Afterglow (after 20ms) 150ppm