Lutetium oxyorthosilicate

Crystal structure
	__ Lu 3+ __ Si 4+ __ O 2−
General
Surname	Lutetium oxyorthosilicate
other names	LSO
Ratio formula	Lu 2 SiO 5
Brief description	trigonal, colorless crystals
External identifiers / databases
EC number	235-337-4
ECHA InfoCard	100.032.113
Wikidata	Q1877799
properties
Molar mass	458.0165 g mol −1
Physical state	firmly
density	7.4 g cm −3
Melting point	2047 ° C
Refractive index	1.82
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Lutetium oxyorthosilicate (LSO) is a silicon - oxygen compound of lutetium .

Doped with cerium , it is suitable as a scintillator material for the detection of gamma rays . LSO was developed in the early 1990s and has since replaced the bismuth germanate (BGO) and gadolinium orthosilicate (GSO) scintillators used in many of the positron emission tomography (PET) systems available today . The refractive index is 1.82, the linear attenuation coefficient µ is 0.87 cm ⁻¹ and the time constant for the decay of a scintillation is 40 ns. The u. a. of atomic number and cross-section dependent photoelectric effect proportion μ _r case of photon energy of 511 keV is 34%. LSO crystals have a trigonal crystal structure and a Mohs hardness of 5.8.

The very short time constant of 40 ns compared to 300 ns with BGO enables smaller coincidence windows in positron emission tomography and thus higher count rates than would otherwise be possible with the same device design. The linear attenuation coefficient µ is, however, lower than that of BGO (0.87 cm ⁻¹ vs. 0.96 cm ⁻¹ ), so that the sensitivity for gamma quanta is somewhat lower.

Lutetium oxyorthosilicate crystallizes in the monoclinic crystal system , space group C 2 / c (space group no. 15) , with the lattice parameters a = 14.28 Å , b = 6.640 Å, c = 10.25 Å and β = 122.2 °. The structure contains isolated O ²⁻ and SiO ₄⁴⁻ ions. Template: room group / 15

literature

Guohao Ren, Laishun Qin, Huanying Li, Sheng Lu: Investigation on defects in Lu ₂ SiO ₅ : Ce crystals grown by Czochralski method. In: Crystal Research and Technology. Volume 41, Number 2, pp. 163-167, February 2006, doi: 10.1002 / crat.200510549

Web links

Patent US6323489 : Single crystal scinitillator. Published November 27, 2001 , Inventor: Kenneth J. McClellan. ‌

Individual evidence

↑ ^a ^b ^c ^d ^e MTI Corporation: New Scintillation Crystal Ce: Lu ₂ SiO ₅ ( MS Word ; 289 kB).
↑ Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of Dilutetium oxide silicate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), retrieved on July 28, 2019, is reproduced from a self-classification by the distributor .
^ Charles L. Melcher: Scintillation Crystals for PET . In: Journal of Nuclear Medicine . tape 41 , no. 6 , 2000, ISSN 0161-5505 , p. 1051-1055 , PMID 10855634 (free full text).
^ ^A ^b William W. Moses: Nuclear Medical Imaging Techniques and Challenges ( Memento of January 31, 2012 in the Internet Archive ). Lawrence Berkeley National Laboratory Department of Functional Imaging, February 9, 2005 (PDF; 9.3 MB).
↑ T. Gustafsson, M. Klintenberg, SE Derenzo, MJ Weber, JO Thomas: Lu ₂ SiO ₅ by single-crystal X-ray and neutron diffraction. In: Acta Crystallographica , C57, 2001, pp. 668-669, doi: 10.1107 / S0108270101005352 .

[CTI-1] MTI Corporation: New Scintillation Crystal Ce: Lu ₂ SiO ₅ ( MS Word ; 289 kB).

[2] Template: CL Inventory / not harmonized There is not yet a harmonized classification for this substance . A labeling of Dilutetium oxide silicate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), retrieved on July 28, 2019, is reproduced from a self-classification by the distributor .

[Melcher-3] Charles L. Melcher: Scintillation Crystals for PET . In: Journal of Nuclear Medicine . tape 41 , no. 6 , 2000, ISSN 0161-5505 , p. 1051-1055 , PMID 10855634 (free full text).

[Moses-4] A ^b William W. Moses: Nuclear Medical Imaging Techniques and Challenges ( Memento of January 31, 2012 in the Internet Archive ). Lawrence Berkeley National Laboratory Department of Functional Imaging, February 9, 2005 (PDF; 9.3 MB).

[5] T. Gustafsson, M. Klintenberg, SE Derenzo, MJ Weber, JO Thomas: Lu ₂ SiO ₅ by single-crystal X-ray and neutron diffraction. In: Acta Crystallographica , C57, 2001, pp. 668-669, doi: 10.1107 / S0108270101005352 .