Search results for "Magnetometer"
showing 10 items of 102 documents
Magnetometry of buried layers—Linear magnetic dichroism and spin detection in angular resolved hard X-ray photoelectron spectroscopy
2012
Abstract The electronic properties of buried magnetic nano-layers were studied using the linear magnetic dichroism in the angular distribution of photoemitted Fe, Co, and Mn 2p electrons from a CoFe–Ir78Mn22 multi-layered sample. The buried layers were probed using hard X-ray photoelectron spectroscopy, HAXPES, at the undulator beamline P09 of the 3rd generation storage ring PETRA III. The results demonstrate that this magnetometry technique can be used as a sensitive element specific probe for magnetic properties suitable for application to buried ferromagnetic and antiferromagnetic magnetic materials and multilayered spintronics devices. Using the same instrument, spin-resolved Fe 2p HAXP…
Graphical Schemes Designed to Display and Study the Long-term Variations of Schumann Resonance
2019
This work proposes and illustrates a graphical approach aimed at studying a wide range of features of the ELF horizontal magnetic field signal recorded at the Sierra Nevada station (Spain). In addition to the traditional long-term variations in the parameters of the first three Schumann resonances (their amplitudes, central frequencies and widths), many other properties such as the saturations of the magnetometers, anomalous values for the parameters or spectra with any kind of particularities are taken into consideration in this work. These features can provide us with complementary information about the long-term variation of Schumann resonances, give an estimation of the extent up to whi…
Superconducting properties of polycrystalline YBCO prepared by a pyrolytic process
1994
Polycrystalline YBCO was prepared by a pyrolytic process starting from citrate and tartrate precursors. The effect of the precursor on the superconducting properties was investigated by means of magnetic measurements using a SQUID magnetometer, a Vibrating-Sample Magnetometer and an a.c. susceptometer. The critical temperature is not affected by the type of precursor (Tc=85 K for both). On the other hand, the precursor plays an important role on the critical current density, which is found to be an order of magnitude higher in the sample obtained from citrates (Jc(77K, H=0)=2.3·104 A/cm2 and 103 A/cm2 for the from-citrate and from-tartrate sample, respectively).
The effect of Fe doping on superconductivity in ZrRuP
2011
Abstract This work reports the structure and superconducting properties of the superconductor ZrRuP doped with Fe; the ZrRu 1− x Fe x P solid solution was investigated by means of X-ray powder diffraction, SQUID magnetometry and Mosbauer spectroscopy. It is shown that the modification of the superconducting properties by doping with Fe is similar to the effect of chemical pressure and that the Fe doped compounds do not show any magnetic ordering.
History dependence of the magnetization of thin HTSC films: an explanation for distorted SQUID signals
1997
Abstract The magnetizations of thin film disk-shaped type-II superconductors in perpendicular magnetic fields are considered by aid of Mikheenko's critical state model which has been corrected by Zhu for the case of a time-varying periodic field. This paper presents the application of this scheme to an arbitrary nonperiodic time dependence H ( t ). We calculate the influence of field inhomogeneities in a magnetometer on the current density distribution of a disk-shaped type-II superconductor. The resulting SQUID pickup signals and magnetic moments are compared to measurements performed on a 200 nm thick YBa 2 Cu 3 O 7 film in the irreversible regime of the phase diagram. Theory and experime…
Microwave-free magnetometry with nitrogen-vacancy centers in diamond
2016
We use magnetic-field-dependent features in the photoluminescence of negatively charged nitrogen-vacancy centers to measure magnetic fields without the use of microwaves. In particular, we present a magnetometer based on the level anti-crossing in the triplet ground state at 102.4 mT with a demonstrated noise floor of 6 nT/$\sqrt{\text{Hz}}$, limited by the intensity noise of the laser and the performance of the background-field power supply. The technique presented here can be useful in applications where the sensor is placed closed to conductive materials, e.g. magnetic induction tomography or magnetic field mapping, and in remote-sensing applications since principally no electrical acces…
Full Tunability of Strain along the fcc-bcc Bain Path in Epitaxial Films and Consequences for Magnetic Properties
2009
Strained coherent film growth is commonly either limited to ultrathin films or low strains. Here, we present an approach to achieve high strains in thicker films, by using materials with inherent structural instabilities. As an example, 50 nm thick epitaxial films of the ${\mathrm{Fe}}_{70}{\mathrm{Pd}}_{30}$ magnetic shape memory alloy are examined. Strained coherent growth on various substrates allows us to adjust the tetragonal distortion from $c/{a}_{\mathrm{bct}}=1.09$ to 1.39, covering most of the Bain transformation path from fcc to bcc crystal structure. Magnetometry and x-ray circular dichroism measurements show that the Curie temperature, orbital magnetic moment, and magnetocrysta…
Hyperfine Paschen-Back regime realized in Rb nanocell
2012
A simple and efficient scheme based on one-dimensional nanometric thin cell filled with Rb and strong permanent ring magnets allowed direct observation of hyperfine Paschen-Back regime on D1 line in 0.5 - 0.7 T magnetic field. Experimental results are perfectly consistent with the theory. In particular, with sigma+ laser excitation, the slopes of B-field dependence of frequency shift for all the 10 individual transitions of 85,87Rb are the same and equal to 18.6 MHz/mT. Possible applications for magnetometry with submicron spatial resolution and tunable atomic frequency references are discussed.
A Gadolinium(III) Complex Based on the Thymine Nucleobase with Properties Suitable for Magnetic Resonance Imaging
2021
The paramagnetic gadolinium(III) ion is used as contrast agent in magnetic resonance (MR) imaging to improve the lesion detection and characterization. It generates a signal by changing the relaxivity of protons from associated water molecules and creates a clearer physical distinction between the molecule and the surrounding tissues. New gadolinium-based contrast agents displaying larger relaxivity values and specifically targeted might provide higher resolution and better functional images. We have synthesized the gadolinium(III) complex of formula [Gd(thy)2(H2O)6](ClO4)3·2H2O (1) [thy = 5-methyl-1H-pyrimidine-2,4-dione or thymine], which is the first reported compound based on gadolinium…
Optically pumped Cs magnetometers enabling a high-sensitivity search for the neutron electric dipole moment
2020
An array of 16 laser-pumped scalar Cs magnetometers was part of the neutron electric dipole moment (nEDM) experiment taking data at the Paul Scherrer Institute in 2015 and 2016. It was deployed to measure the gradients of the experiment's magnetic field and to monitor their temporal evolution. The originality of the array lies in its compact design, in which a single near-infrared diode laser drives all magnetometers that are located in a high-vacuum chamber, with a selection of the sensors mounted on a high-voltage electrode. We describe details of the Cs sensors' construction and modes of operation, emphasizing the accuracy and sensitivity of the magnetic-field readout. We present two app…