Eu: SrI2 crystal is a kind of scintillation crystal with excellent performance. It has the advantages of large atomic numbers, high light output, extremely low energy resolution, and small afterglow time. Its disadvantage is that it is very deliquescent and has relatively long decay time. Therefore, Eu:SrI2 crystal is very suitable for nuclear technology fields that do not require high decay time but high light output and energy resolution performance, such as gamma-ray spectroscopy, element isotope discrimination, and scintillation detectors for safety inspection equipment. It has potential applications in industrial and medical CT, ultra-high-resolution X-ray imaging, and other fields.

The emission wavelength of Eu:SrI2 crystal is between 400-500nm, which matches the spectral sensitive area of mainstream photomultiplier tube (PMT), which is conducive to scintillation photon detection. At the same time, unlike most rare earth-doped scintillation materials, Eu2+ in Eu: SrI2 crystal is doped as SrI2 activator. Because of its serious radiation trap effect, a high concentration of Eu2+ will reduce its scintillation performance, generally considered to be 5%mol concentration is its optimal concentration.


Material Features

Chemical formulaEu: SrI2
Density (g/cm3)4.55
Melting point (℃)538
Atomic number (effective)49
Thermal expansion coeff (C-1)21.64*10-6

Scintillator Properties

Wavelength(Max. emission) (nm)435
Wavelength range(nm)400~480
Decay time(ns)1200
Light yield(photons/keV)80
Light output relative to Nal(Tl) (%)130
Refractive index1.85
Radiation length(cm)1.95
Energy resolution(%)<3
X-ray Absorption Coef. at 100 KeV(cm-1)2.88
X-ray Absorption Coef. at 662 KeV(cm-1)0.13



  • Good Energy Resolution
  • Stable Physical and Chemical Properties
  • High Thermal Conductivity
  • High Mechanical Strength (High Young’s Modulus, Large Bending Strength)
  • Fast Decay Time and High Sensitivit


  • Hand-held high-precision nuclide identification instrument
  • Portable gamma spectrometer
  • Online measurement of radioactive waste water
  • UAV radioactive nuclear emergency measurement
  • Element isotope screening
  • Safety inspection
  • Industrial and medical X-ray tomography
  • Ultra-high resolution X-ray imaging
  •  X-ray, β-ray Detection
  • Photomultiplier Tubes
  • Photoelectric Counter
  • Scintillation Screen
  • LED illumination


[1]  Nagai S ,  Kawamura K ,  Kimura Y , et al. An advanced ionizing radiation monitoring network based on using SrI2(Eu)/MPPC module[J]. Surface & Interface Analysis, 2016, 48(11):1263-1268.
[2]  Cherepy N J ,  Payne S A ,  Sturm B W , et al. Comparative gamma spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded plastic scintillators[C]// Nuclear Science Symposium Conference Record. IEEE, 2010.
[3] Takayuki, Yanagida, Masanori, et al. Comparative study of nondoped and Eu-doped SrI2 scintillator[J]. Optical Materials, 2016.

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