X-ray excited optical fluorescence spectrometry. Scope of application to trace rare earth determinations

The x-ray excited-optical luminescence of lanthanides in phosphors prepared from yttrium oxide and iron transition-group oxides. Application to the determination of lanthanides in iron and its alloys

“…The XEOL spectra were excited and observed under the same experimental conditions previously described (1,8).…”

“…The lanthanide elements are especially well suited to this analytical technique because they produce relatively sharp line luminescence when the phosphor host containing the lanthanide is excited by ultraviolet or x-ray radiation, or by energetic particle bombardment. Numerous phosphor compositions have been prepared, and many have been evaluated for possible analytical applications (1)(2)(3)(4)(5)(6)(7). Other than the SrO-ThOa• C^Os system we reported previously (1), to our knowledge no phosphor containing large amounts of the iron group of transition elements has been reported.…”

“…Numerous phosphor compositions have been prepared, and many have been evaluated for possible analytical applications (1)(2)(3)(4)(5)(6)(7). Other than the SrO-ThOa• C^Os system we reported previously (1), to our knowledge no phosphor containing large amounts of the iron group of transition elements has been reported. This absence is understandable because the presence of these elements, even at low concentration, tends to suppress the luminescence of the lanthanides (8)(9)(10).…”

Determination of trace rare earth impurities in lutetium by x-ray excited optical luminescence

“…20* [36][37][38][39][40][41][42][43][44][45][46][47] An atom upon a b s o r p t i o n of an X-ray photon may e j e c t one' photoelectron w i t h a c e r t a i n k i n e t i c energy. I f t h i s i r r a d i a t e d atom o r i o n is a component of a solid, c r y s t a l , t h e photoelectron does n o t n e c e s s a r i l y escape from t h e c r y s t a l , b u t can impart random amounts of .its k i n e t i c energy, ranging from 1 0 t o .…”

“…a s i m p u r i t i e s i n a h o s t , t h e luminescence i s enhanced. 36 he m o b i l i t y , of t h e secondary e x c i t a n t s and t h e s h o r t l i f e t i m e of t h e e x c i t e d s t a t e s of t h e ions r e s u l t s i n repeated e x c i t a t i o n of t h e r a r e e a r t h i o n . a n d t h e r e f o r e i n a s t r o n g luminescence.…”