Bismuth Silicate & Bismuth Germanate
BSO & BGO
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

Item

BGO

Bi4Ge3O12

CWO

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

X-ray CT

Which enables the use

 

Of silicon photo diode