High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

The overall goal of this procedure is to perform high resolution nuclear magnetic resonance experiments in high pressure anvil cells. This is accomplished by first preparing a radio frequency micro coil of several turns from 18 micrometer copper wire. The second step is to place the micro coil directly in the middle of the high pressure sample cavity and connect it to the hot wire and make an electrical ground.

Next, the anvil cell is filled with the sample ruby pressure sensors and pressure transmitting media. The final step is to pressurize the anvil cell by tightening four alan screws. Ultimately, the anvil cell can be mounted on a standard nuclear magnetic resonance or NMR probe, allowing for frequency tuning and impedance matching.

The main advantage of this technique over existing methods like split bear coils or single loop resonates with pressure cells is that in our approach, the filling factor of our detection coil can be dramatically increased, allowing for high sensitivity and r and n cells house. This method can help answer key questions in the field of condensed metaphysics, in particular solid state physics and examples such as high temperature superconductivity. First, fix the piston and XY plate in the mounting tools and insert the bowler type anils in the seating area.

After ensuring that each anil sits firmly in the backing plates, glue both anvils to their seats using epoxy resin cure for two hours at 65 degrees Celsius in a furnace or a sufficient anvil alignment. Use the M1 set screws to align the backing plates and monitor the parallelism of both anvils. Next, drill one millimeter holes into an Anil copper beryllium chip.

For the brass guide pins insert three five millimeter long pieces of one millimeter diameter non insulated copper wire into the holes to serve as guide pins for the copper beryllium gasket. Check for proper grounding between the guide pins and the cell body. If a DC resistance of about 0.1 ohms is not observed at a small amount of conductive silver to improve the resistance following this place the copper beryllium chip on top of the moisten anvil and close the cell.

Using a hydraulic press, pressurize the gasket to about one eighth of the cullet diameter. For maximized working stability, monitor the actual thickness of the indentation using a micrometer caliper. Next drill a hole of the appropriate diameter in the center of the indentation.

Carve two channels into the pre indented gasket, deepen off to accommodate the 18 micrometer copper wire of the micro coil. Then harden the prepared gasket at 617 Kelvins for two to three hours in a furnace. At this point, throw a piece of one millimeter copper wire through the feed through of the piston.

Fix the copper wire with epoxy resin and cure it as described previously. After choosing an all that has the desired diameter for the micro coil, fix it between a pair of rotatable chuck jaws. Then glue one end of the 18 micrometer copper wire onto the chuck jaws while holding the other end, and rotate the chuck jaw so that the wire is coiled onto the oil.

When the micro coil is of the desired geometry, fix the other end of the wire onto the glue. Use diluted varnish to fix the coil by applying a small amount on top of the windings. Then remove the coil carefully from the oil using Teflon tape.

Following this, lay some epoxy resin in the channels of the gasket. Place the micro coil inside the sample chamber and fix the leads into the channels. After curing the epoxy resin sold a one lead of the micro coil to the hot wire and the other to a guide pin.

Add some silver conductive paste on top of each junction, allowing it to cure for a few minutes. Once the silver conductive paste is cured, seal both junctions with a small amount of epoxy resin. After curing the epoxy, check the DC resistance of the coil.

After every step, place the sample in the micro coil, add finely ground ruby powder to the sample for pressure calibration. Finally, flood the sample chamber with paraffin oil to ensure nearly hydrostatic conditions up to nine giga pascals. Then close the cell carefully.

Following this, slightly tighten the M three Allen countersunk screws for pressurization. Fix the cell in a vice, then tighten two opposing screws. Pairwise, place the pressurized cell in an appropriate cell holder.

Adjust the position of the cell so that the laser beam reaches the sample chamber. Next, use the fine adjustment table to focus the ruby powder in the laser beam. Monitor the ruby photo luminescence spectrum using the corresponding spectrometer software.

Extract the actual pressure in the sample cavity from the observed spectral shift of the Ruby R one and R two lines. After AC equilibrating the pressurized cell for at least 12 hours, mount it onto a typical NMR probe. Sold the hot wire to the probe.

Then check for proper electrical contact between the cell and the probe. Following this perform standard NMR experiments. The 27 aluminum NMR Spectra acquired up to 10.1 giga Pascal pressure is displayed here.

The observed total lime widths increased from about 77 parts per million, up to 145 parts per million. At this pressure recorded free induction decay at magnetic fields of 11.74 Tesla 17.6 Tesla, and the difference between both are shown here, obtained spin echoes at elevated pressure for different pulse separation times are shown here. The observed 17 oxygen in a mass spectrum of the high temperature superconductor, yttrium barium copper oxide, 1 2 4 8 at 6.3 giga Pascals, and 110 Kelvins has an observed line width of about 1, 500 parts per million border.

Distinct oxygen signals could be identified even at higher pressures and at temperatures between 105 and 110 Kelvins. Typical gallium NMR spectra of room temperature and at 1.8 giga pascal pressure are displayed here. A typical result of a mutation experiment with varying pulse length is shown here.

The dependence of the observed signal intensities obtained in a PII half inversion recovery experiment or increasing pulse separation times is displayed here. Once mastered, the self preparation can be done within 12 hours if it's performed properly. Well, with such a procedure, it's important to know that you need to have a good hands-on graduate student available.