The Distribution of Cu(II) on Boehmite and Silica Surfaces: Correlating EPR Signal Loss with the Effective Bohr Magneton Number of Sorbed Ions
✍ Scribed by Kang Xia; Robert W. Taylor; William F. Bleam; Philip A. Helmke
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 130 KB
- Volume
- 199
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
spin relaxation. Exchange interactions arise only in con-The effective Bohr magneton number m eff of Cu(II) adsorbed densed, polynuclear phases. at the boehmite/water interface is 14% to 21% less than antici-An earlier study (8) of Cu(II) sorbed to boehmite ( gpated for a uniform dispersal of Cu(II) ions throughout the inter-AlOOH) reports 85% lost EPR intensity at a Cu(II) surface face. Insufficient evidence for exchange coupling indicates the lost excess of 1.86 mmol/m 2 . Signal loss, in this case, cannot be electron paramagnetic resonance signal intensity must largely reattributed to exchange-coupling because Cu K-edge X-ray sult from spin-spin relaxation. Polynuclear Cu(II) clusters at absorption spectra reveal no evidence of polynuclear Cu(II) the silica/water interface are superparamagnetic with a blocking clusters at the boehmite/water interface (8).
temperature between 5 K and 7 K. Superparamagnetic Cu(II)
Table 1 lists selected XAS studies reporting evidence for clusters at the silica/water interface do not saturate at magnetic fields as high as 10,000 G.