A high temperature cell for simultaneous electrical resistance and neutron diffraction measurements

Abstract

An in situ cell that allows the electrical resistance of a sample pellet to be measured while performing neutron diffraction experiments has been developed at the ISIS pulsed neutron source. The sample is held between two spring loaded platinum electrodes embedded in a boron nitride clamp assembly with the resistance measured using the four-probe method. An outer quartz glass jacket allows the atmosphere within the sample enclosure to be controlled, and the entire device can be accommodated within a standard ISIS neutron furnace for measurements at temperatures up to 1270 K. The operation of this cell is illustrated using data for the structural, magnetic, and electrical properties of chalcopyrite CuFeS(2) collected over the temperature range of 398-873 K on the Polaris powder diffractometer at ISIS.

New high temperature gas flow cell developed at ISIS

“…Thus, in addition to the field of SOFC materials mentioned above, the apparatus described in this paper is likely to find widespread applications within research areas such as high temperature superconductors, multiferroic compounds, and mineralogy. A number of development projects are also underway to expand the range of science to be addressed, including the use of controlled humid atmospheres for the study of proton conducting ceramics for fuel cell applications and the combined use of the gas panel with an in-situ resistance measurement cell [4] to simultaneously probe the structural and conducting properties of materials as a function of oxygen partial pressure and temperature.…”

“…Facilities which permit diffraction studies to be performed under controlled atmospheres have been developed at a number of neutron sources (see, for example, [2][3]) but tend to be rather less routinely used. Nevertheless, they offer an extremely powerful approach to probe the relationship between crystal structure and bulk properties of materials, particularly if the latter are simultaneously monitored [4]. This paper describes the design and construction of a flow-through quartz gas cell for use at ISIS, together with its complementary flow control and monitoring system which allows the oxygen partial pressure within a flowing gas stream around the sample to be varied.…”

Application of combined neutron diffraction and impedance spectroscopy for in-situ structure and conductivity studies of La2Mo2O9

“…The impedance measurement rig, designed and built at ISIS [8], was mounted vertically in the furnace which was put in the sample tank. The neutron diffraction data were recorded on the middle of the sample to avoid collecting additional diffraction data from the platinum electrodes on both sides of the pellet.…”

“…The purpose of this work was to investigate the crystal structure and the simultaneous ionic conductivity change during the phase transition in La 2 Mo 2 O 9 using a combined in situ neutron diffraction and AC impedance spectroscopy, which is based upon a simultaneous neutron diffraction and four-probe electrical resistance measurement technique [8]. Therefore, both crystal structure and conductivity can be obtained simultaneously, from which a direct correlation between the two can be acquired.…”

Fluorites: Superionics and Conduction Processes

“…In these cases, there are clear advantages to performing studies of the conductivity and defect properties simultaneously. To this end, an in-situ cell to measure the conductivity of polycrystalline samples during neutron powder diffraction studies has been developed at ISIS (see figure 5) [36]. This device holds the pellet sample between two spring loaded platinum contacts, with the clamp assembly constructed of neutron absorbing boron nitride to avoid contamination of the measured diffraction pattern by Bragg peaks from the cell components.…”