Editing Samarium (section)

===Storage phosphor===
In 2007 it was shown that nanocrystalline BaFCl:Sm{{sup|3+}} as prepared by co-precipitation can serve as a very efficient X-ray [[Photostimulated luminescence|storage phosphor]].<ref>{{cite journal|last1=Riesen|first1=Hans |last2=Kaczmarek|first2=Wieslaw |title=Efficient X-ray Generation of Sm{{sup|2+}} in Nanocrystalline BaFCl/Sm{{sup|3+}}: a Photoluminescent X-ray Storage Phosphor|journal=Inorganic Chemistry|date=2007-08-02|volume=46|issue=18|pages=7235–7 |doi=10.1021/ic062455g|pmid=17672448}}</ref> The co-precipitation leads to nanocrystallites of the order of 100–200&nbsp;nm in size and their sensitivity as X-ray storage phosphors is increased a remarkable ~500,000 times because of the specific arrangements and density of defect centers in comparison with microcrystalline samples prepared by sintering at high temperature.<ref>{{cite journal|last1=Liu|first1=Zhiqiang |last2=Stevens-Kalceff|first2=Marion |last3=Riesen|first3=Hans |title=Photoluminescence and Cathodoluminescence Properties of Nanocrystalline BaFCl:Sm3+ X-ray Storage Phosphor|journal=Journal of Physical Chemistry C|date=2012-03-16|volume=116|issue=14 |pages=8322–8331|doi=10.1021/jp301338b}}</ref> The mechanism is based on reduction of Sm{{sup|3+}} to Sm{{sup|2+}} by trapping electrons that are created upon exposure to ionizing radiation in the BaFCl host. The {{sup|5}}D{{sub|J}}–{{sup|7}}F{{sub|J}} f–f luminescence lines can be very efficiently excited via the parity allowed 4f{{sup|6}}→4f{{sup|5}}5d transition at ~417&nbsp;nm. The latter wavelength is ideal for efficient excitation by blue-violet laser diodes as the transition is electric dipole allowed and thus relatively intense (400 L/(mol⋅cm)).<ref>{{cite journal|last1=Wang|first1=Xianglei |last2=Liu|first2=Zhiqiang |last3=Stevens-Kalceff|first3=Marion |last4=Riesen|first4=Hans |title=Mechanochemical Preparation of Nanocrystalline BaFCl Doped with Samarium in the 2+ Oxidation State|journal=Inorganic Chemistry|date=August 12, 2014 |volume=53|issue=17|pages=8839–8841 |doi=10.1021/ic500712b|pmid=25113662}}</ref>
The phosphor has potential applications in personal dosimetry, dosimetry and imaging in radiotherapy, and medical imaging.<ref>{{cite web|title=Dosimetry&Imaging Pty Ltd|url=http://www.oelimaging.com |access-date=2018-11-28|archive-url= https://web.archive.org/web/20170926094926/http://oelimaging.com/ |archive-date=2017-09-26}}</ref>