Laser-Sintered Bismuth Germanate Ceramics as Scintillator Devices

• Published in: Journal of the American Ceramic Society Vol. 87; no. 6; pp. 1076 - 1081
• Main Authors: Macedo, Zélia Soares, Silva, Ronaldo Santos, Valerio, Mário Ernesto Giroldo, Martinez, André Luiz, Hernandes, Antonio Carlos
• Format: Journal Article
• Language: English
• Published: Westerville, Ohio American Ceramics Society 01.06.2004; Blackwell; Wiley Subscription Services, Inc
• Subjects: Applied sciences; bismuth; Building materials. Ceramics. Glasses; Ceramic industries; Ceramic sintering; Chemical industry and chemicals; Electrotechnical and electronic ceramics; Exact sciences and technology; germanates; lasers; Luminescence; Radiation; Technical ceramics; Scanning electron microscopy; Transparency; Bismuth germanates; Laser irradiation; Experimental study; Density; X ray diffraction; Oxide ceramics; Dilatometry; Radiation detector; Scintillator; Sintering; Optical properties; Optical ceramics; Thermal analysis; Manufacturing; Microstructure; Electroceramics; Thermoluminescence
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1551-2916.2004.01076.x

We have investigated the potential use of Bi4Ge3O12 (BGO) laser‐sintered ceramics in scintillator devices for radiation detection. Relevant results from the characterization made during the ceramic processing are presented, such as particle size analysis, X‐ray diffraction studies, and thermal analysis. Furthermore, we have compared the microstructure, relative density, thermoluminescent (TL) emission, and transparency degree of ceramic bodies sintered by CO2 laser heating with a reference set of ceramics sintered in an electrical furnace, and also with single crystals grown by the Czochralski technique. It was observed that the laser‐sintered BGO presented a relative density of 98% (±2%), better pore shrinkage, larger grains, and light transmission intensity 1.5 times higher than the BGO ceramics sintered in a furnace. The TL curves of all samples irradiated with UV and β−rays presented peaks at 75°, 102°, and 143°C, and provided strong indication that the intergrain defects have the same nature of the bulk defects and do not contribute with new traps in the temperature range studied. The relative areas of the total TL emission after β irradiation were 6,0:4,4:1 for the reference ceramic, laser sintered ceramic, and single crystal, respectively. For UV irradiated samples, this relation was 7,1:4,7:1. From these results, we have concluded that laser‐sintered ceramics have an amount of charge traps lower than the conventionally sintered BGO samples, thus having a higher radioluminescence yield.