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Related Experiment Video

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Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions

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Pressure effects in the isoelectronic REFe0.85Ir0.15AsO system.

Beatrice Maroni¹, Daniele Di Castro, Michael Hanfland

¹Department of Chemistry, and INSTM Unit of Pavia, viale Taramelli 10/16, 27100 Pavia, Italy.

Journal of the American Chemical Society

|February 24, 2011

Summary

Investigating iron pnictide superconductors revealed that chemical and hydrostatic pressure similarly affect critical temperature. This finding challenges current understanding of superconductivity mechanisms in these high-temperature materials.

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

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Published on: October 10, 2014

Area of Science:

Condensed Matter Physics
Materials Science
Superconductivity

Background:

Iron pnictides are a class of high-temperature superconductors with potential applications.
Understanding the factors influencing their critical temperature (Tc) is crucial for advancing superconductivity research.
Previous studies have explored pressure effects, but systematic comparisons across different structural modifications are limited.

Purpose of the Study:

To systematically investigate the effects of chemical and hydrostatic pressure on the critical temperature (Tc) of 1111-family iron pnictides.
To compare the pressure response of isoelectronic samples with varying rare earth elements to doped samples.
To gain insights into the fundamental mechanism driving superconductivity in iron-based superconductors.

Main Methods:

Systematic application of chemical pressure (via varying rare earth elements) and hydrostatic pressure.
Measurement of critical temperature (Tc) under varying pressure conditions.
Comparative analysis of Tc trends as a function of pressure for different sample compositions.

Main Results:

A striking similarity was observed in the trend of critical temperature versus hydrostatic pressure for isoelectronic samples with different rare earths (RE).
This trend mirrored that of the SmFeAsO(1-x)F(x) series, where different doping levels were used.
Isoelectronic substitution on the rare earth site mimics the effect of doping on the critical temperature under pressure.

Conclusions:

The observed similarity suggests a universal mechanism influenced by pressure in 1111 iron pnictides, regardless of the specific rare earth element or doping level.
These findings challenge existing models and open new avenues for exploring the origin of high-temperature superconductivity in these materials.
Further theoretical and experimental work is needed to fully elucidate the underlying microscopic mechanisms.