Bismuth Silicate & Bismuth Germanate ( BSO & BGO )

Bismuth Bismuth Bismuth
Bismuth Germanate (BGO) Bismuth Germanate (BGO) Bismuth Silicate (BSO)
Basic Properties
Crystal Bi12SiO20 (BSO) Bi12GeO20 (BGO)
Symmetry Cubic, 23 Cubic, 23
Melting Point 900 °C 930 °C
Density 9.2 g/cm³ 9.2 g/cm³
Mohs Hardness 4.5 4.5
Transparencey Range 450 – 7500 nm 470 – 7500 nm
Transmittance at 633 nm 69% 67%
Refractive Index at 633 nm 2.54 2.55
Dielectric Constant 56 40
Electro-optic Coefficient r41 = 5 x 10-12 m/V r41 = 3.4 x 10-12 m/V
Resistivity 5 x 1011W-cm 8 x 1011W-cm
Loss Tangent 0.0015 0.0035
Comparison, BGO, CWO      
Properties of scintillation Crystals      
Crystal BGO CWO  
Item Bi4Ge3O12 CdWO4  
Effective  atomic number 75 65  
Density  (g/cm³) 7.13 7.90  
Decay  constant (ns) 300 5000  
Light output  (%) 12 39  
Maximum  emission wavelagth (nm) 480 540  
Refractive  index 2.15 5.25  
Sensitivity  to moisture None None  
Cleavage None Yes  
Attenuation coefficient X-ray  150 KeV 9.84 7.64
(cm-1 Y-ray  511 KeV 0.955 0.856
  Characteristics Application  
GSO Short decay time High performance  
Positron CT      
BGO Better absorption of Positron CT  
Radioactive rays Detection of high energy    
Because of its large Partidle in the field of    
Effective atomic number Fundamental physics    
CWO Large light output,
which enables the use
of silicon photo diode
X-ray CT