Proton-induced magnetic order in carbon: SQUID measurements
نویسنده
چکیده
In this work we have studied systematically the changes in the magnetic behavior of highly oriented pyrolytic graphite (HOPG) samples after proton irradiation in the MeV energy range. Superconducting quantum interferometer device (SQUID) results obtained from samples with thousands of localized spots of micrometer size as well on samples irradiated with a broad beam confirm previously reported results. Both, the paraand ferromagnetic contributions depend strongly on the irradiation details. The results indicate that the magnetic moment at saturation of spots of micrometer size is of the order of 10 emu.
منابع مشابه
Current-induced SQUID behavior of superconducting Nb nano-rings
The critical temperature in a superconducting ring changes periodically with the magnetic flux threading it, giving rise to the well-known Little-Parks magnetoresistance oscillations. Periodic changes of the critical current in a superconducting quantum interference device (SQUID), consisting of two Josephson junctions in a ring, lead to a different type of magnetoresistance oscillations utiliz...
متن کاملMagnetic field measurements using very sensitive SQUIDs
SQUID systems, using either high temperature or low temperature superconductors, were developed for sensitive measurements in magnetically disturbed environments. They include the SQUIDs and fast SQUID electronics. Magnetometer SQUID systems are used for geophysical sounding, where they show superiority when compared to conventional induction coils for very deep sounding or fast measurement. Hi...
متن کاملEnhancement of SQUID-detected NMR signals with hyperpolarized liquid 129Xe in a 1 microT magnetic field.
We report an enhancement of proton NMR signals by a factor of 10(6) by cross polarization with hyperpolarized liquid 129Xe in an ultralow magnetic field of 1 microT. The NMR signals from cyclopentane, acetone, and methanol are detected using a commercial high-T(c) SQUID magnetometer with a signal-to-noise ratio of up to 1000 from a single 90 degrees tipping pulse. This technique allows a wide r...
متن کاملLow-noise Cryocooler-cooled Compact SQUID-NDE System for Carbon-Fiber Composites
A low-noise and compact SQUID-NDE system cooled by a cryocooler has been developed for practical NDE of carbon-fiber composites. In order to suppress the magnetic noise due to a cryocooler, a planar high-Tc SQUID gradiometer, coaxial pulse tube cryocooler, and SQUID stage separated from the cold head of the cryocooler were introduced. There was no increase of magnetic flux noise due to the cryo...
متن کاملDevelopment and Applications of SQUIDs in Korea
As sensitive magnetic sensors, magnetometers based on superconducting quantum interference devices can be used for the detection of weak magnetic fields. These signals can be generated by diverse origins, for example, brain electric activity, myocardium electric activity, and nuclear precession of hydrogen protons. In addition, weak current induced in the low-temperature detectors, for example,...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006