System for ESR measurements at hydrostatic pressures to 60 kilobars

Abstract

A single-crystal sapphire serves both as a solid microwave cavity (X band) and an anvil in a Bridgman-anvil pressure geometry. A metal gasket is used in a manner similar to its use in the diamond-anvil pressure cell, and single-crystal samples are subject to purely hydrostatic pressures. The ruby-fluorescence pressure-measurement technique is utilized. Sample size is limited to a disk approximately 0.6 mm in diameter and 0.1 mm thick. ESR data on Cr(3+) in ruby to 60 kilobars are given as an illustration of the precision and data quality. Line widths and profiles, as well as line positions, are meaningful. Very little degradation of the data is experienced at the higher pressures. The first and second derivatives of the zero-field splitting (delta) of the states in ruby with pressure are measured as ddelta/dP= (6.70+/-0.08) x 10(-4) cm(-1) kilobar(-1) and d(2)delta/dP(2)= (-2.44+/-0.30) x10(-6) cm(-1) kilobar(-2) at P=0. The gyromagnetic ratio g(11) is shown to experience a fractional change less than 2 x 10(-4) to 60 kilobars.

Dielectric resonator-based resonant structure for sensitive ESR measurements at high-hydrostatic pressures

“…6-8 GPa for the cavitybased ESR high-pressure systems was established while using a solid pressure-transmitting medium and a set of Bridgman-type anvils made of Al 2 O 3 that were directly incorporated into the resonant cavity [18][19][20].…”

Development of high-pressure and high-field ESR system using SQUID magnetometer

“…Since the first high-pressure ESR measurement was performed in 1957 [6], several kinds of high-pressure ESR systems have been offered. Most of these systems combine a pressure cell with a resonator, and there are two major routes to combine them [7][8][9][10][11][12][13][14]. One route is to use the pressurized resonant cavity, which is a cylindrical or coaxial resonant cavity filled with a low-loss dielectric material such as sapphire that acts as a pressure support [6][7][8][9][10].…”

“…Most of these systems combine a pressure cell with a resonator, and there are two major routes to combine them [7][8][9][10][11][12][13][14]. One route is to use the pressurized resonant cavity, which is a cylindrical or coaxial resonant cavity filled with a low-loss dielectric material such as sapphire that acts as a pressure support [6][7][8][9][10]. For instance, there are Xband ($10 GHz) ESR systems equipped with pressurized resonant cavities, that enable one to make measurements up to 6 GPa at room temperature [9], up to 0.4 GPa at 4 K [10], and so on.…”

Development of High-Field ESR System Using SQUID Magnetometer and its Application to Measurement under High Pressure

“…The pressure is one of the most important parameters in the solid state physics because it changes the interactions between the electron spins continuously and it sometimes leads to novel physical phenomena [19][20][21][22]. Although high-pressure ESR is a powerful means to observe the spin system subjected to the pressure microscopically, it usually needs specialized equipments [10][11][12][13][14][15][16][17][18]. On the contrary, the SQUID-ESR can be applied to the high-pressure ESR very easily.…”

“…Moreover, the system can be applied to the high pressure ESR measurement without difficulty by using a piston cylinder pressure cell. This is another advantageous point as compared with other ESR systems because the high-pressure ESR usually needs specialized equipments [10][11][12][13][14][15][16][17][18]. In this paper, we show the outline of the system and its application example.…”