Optically detected magnetic resonance (ODMR) of the lowest doublet excited state of tris(acetylacetonato)chromium(III)

✍ Scribed by R.A. Fields; C.J. Winscom; E. Haindl; M. Plato; K. Möbius

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 650 KB
• Volume: 124
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(86)85130-2

✦ Synopsis

A phosphorescence line-narrowing technique involving direct quartet ground state to doublet excited state pumping, is used to resolve completely optical-Zeeman components at field strengths compatible with Q-band EPR spectroscopy. By incorporating this technique, ODMR of the lowest doublet excited state of Cr 3+ ions in an organometallic host crystal (tris(acetylacetonato)aluminum(III))

has been obtained for several magnetic field orientations. Selective, direct optical pumping shows that the three prominent, close-lying phosphorescence bands at 773, 776 and 778 nm correspond to three zero-phonon origins. ODMR performed on the 778 nm origins yields the values \g i I= 1.921+ 0.003, lg ,, I= 1.60 f 0.03 for the excited-state g-tensor and provides an order of magnitude estimate of = 10 ~LS for the excited-state spin-latttce relaxation time.