Impact of resonator on direct-detected rapid-scan EPR at 9.8 GHz
Impact of resonator on direct-detected rapid-scan EPR at 9.8 GHz
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DOI：
10.1007/bf03166759
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发表时间：
2005-01-01
影响因子：
1
通讯作者：
Eaton, SS
中科院分区：
文献类型：
--
作者：
Joshi, JP;Eaton, GR;Eaton, SS
在Broker E580光谱仪上获得9.8 GHz下的快速扫描电子顺磁共振光谱。在正弦扫描的中心，以3.4 - 10（3）和7.5 - 10（5）G/s之间的扫描速率记录酞菁锂（LiPc）针（T-1 = 8 μ s，T-2 = 3.4 μ s）和0.2mM的Nyc三芳基甲基（三苯甲基-CD 3）自由基水溶液（T-1 = 11.5 μ s，T-2 = 8 μ s）的光谱。用开口环谐振器、矩形谐振器和介质谐振器获得LiPc的信号。在更快的扫描速率下，高Q介质谐振器的小带宽滤除快速扫描信号的高频分量。快速变化的磁场引起的场不均匀性随着扫描速率的增加而增加，并且介质和开口环谐振器的场不均匀性比矩形谐振器的场不均匀性更大。用矩形谐振器记录三苯甲基-CD 3的数据。扩展的三苯甲基样品，约3毫米长，显示出更大的影响，磁场的不均匀性比小的LiPc晶体。
Rapid-scan electron paramagnetic resonance spectra at 9.8 GHz were obtained on a Broker E580 spectrometer. Spectra of lithium phthalocyanine (LiPc) needles (T-1 = 8 mu s, T-2 = 3.4 mu s) and of a 0.2 mM aqueous solution of Nycomed triarylmethyl (trityl-CD3) radical (T-1 = 11.5 mu s, T-2 = 8 mu s) were recorded at scan rates between 3.4 - 10(3) and 7.5 - 10(5) G/s at the center of sinusoidal scans. Signals for LiPc were obtained with a split-ring resonator, a rectangular resonator and a dielectric resonator. At faster scan rates the small bandwidth of the high-Q dielectric resonator filters out high-frequency components of the rapid-scan signals. Field inhomogeneities induced by the rapidly changing magnetic field increase with scan rate and are greater with the dielectric and split-ring resonators than with the rectangular resonator. Data for trityl-CD3 were recorded with the rectangular resonator. The extended trityl sample, about 3 mm long, shows larger effects of magnetic field inhomogeneities than the small LiPc crystals.