Design for a multifrequency high magnetic field superconducting quantum interference device-detected quantitative electron paramagnetic resonance probe: Spin-lattice relaxation of cupric sulfate pentahydrate (CuSO4⋅5H2O)
Design for a multifrequency high magnetic field superconducting quantum interference device-detected quantitative electron paramagnetic resonance probe: Spin-lattice relaxation of cupric sulfate pentahydrate (CuSO4⋅5H2O)
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多频强磁场超导量子干涉装置检测定量电子顺磁共振探针设计：五水硫酸铜（CuSO4·5H2O）的自旋晶格弛豫
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
S. Russek
中科院分区：
文献类型：
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作者：
B. Cage;S. Russek
设计了一种用于高磁场、高频率下电子顺磁共振（EPR）定量测定的光谱仪。它使用超导量子干涉装置（SQUID）来测量作为外加磁场和微波频率函数的磁矩。我们使用粉状的2,2-二苯基-1-吡啶酰肼来证明在3t磁场下g张量各向异性的分辨率为1mt，灵敏度为每0.1 mT 1014个自旋。我们演示了95 GHz和141 GHz的多频操作。利用五水硫酸铜（铜矿）CuSO4⋅5H2O的排列单晶，我们证明了该光谱仪能够在4 ~ 200 K范围内进行EPR线形分析，并且在100 K时符合洛伦兹线形。在100 K以下，我们观察到谱线加宽、g位移和光谱分裂，所有这些都与已知的低维相变相一致。利用SQUID磁强计和超导磁体，我们提高了一个数量级。
We have designed a spectrometer for the quantitative determination of electron paramagnetic resonance (EPR) at high magnetic fields and frequencies. It uses a superconducting quantum interference device (SQUID) for measuring the magnetic moment as a function of the applied magnetic field and microwave frequency. We used powdered 2,2-diphenyl-1-picrylhydrazyl to demonstrate resolution of g-tensor anisotropy to 1 mT in a magnetic field of 3 T with a sensitivity of 1014 spins per 0.1 mT. We demonstrate multifrequency operation at 95 and 141 GHz. By use of an aligned single crystal of cupric sulfate pentahydrate (chalcanthite) CuSO4⋅5H2O, we show that the spectrometer is capable of EPR line shape analysis from 4 to 200 K with a satisfactory fit to a Lorentzian line shape at 100 K. Below 100 K, we observed line-broadening, g shifts, and spectral splittings, all consistent with a known low-dimensional phase transition. Using SQUID magnetometry and a superconducting magnet, we improve by an order of magnitude th...