High-resolution thermal expansion measurements under Helium-gas pressure

Abstract

We report on the realization of a capacitive dilatometer, designed for high-resolution measurements of length changes of a material for temperatures 1.4 K $\le T\le$ 300 K and hydrostatic pressure $P\le$ 250 MPa. Helium (${}^4$He) is used as a pressure-transmitting medium, ensuring hydrostatic-pressure conditions. Special emphasis has been given to guarantee, to a good approximation, constant-pressure conditions during temperature sweeps. The performance of the dilatometer is demonstrated by measurements of the coefficient of thermal expansion at pressures $P\simeq$ 0.1 MPa (ambient pressure) and 104 MPa on a single crystal of azurite, Cu${}_3$(CO${}_3$)${}_2$(OH)${}_2$, a quasi-one-dimensional spin S = 1/2 Heisenberg antiferromagnet. The results indicate a strong effect of pressure on the magnetic interactions in this system.

8 pages, 7 figures, published in Rev. Sci. Instrum with minor changes

References in corpus (10)

• Quantum Criticality in Heavy Fermion Metals
• Pressure induced superconductivity in CaFe${}_2$As${}_2$
• Unconventional critical behaviour in a quasi-two-dimensional organic conductor
• First order structural phase transition in CaFe${}_2$As${}_2$
• The Absence of Superconductivity in Single Phase CaFe2As2 under Hydrostatic Pressure
• Nature of the spin dynamics and 1/3 magnetization plateau in azurite
• Anomalous Lattice Response at the Mott Transition in a Quasi-2D Organic Conductor
• Scaling theory of the Mott transition and breakdown of the Grüneisen scaling near a finite-temperature critical end point
• Universality of liquid-gas Mott transitions at finite temperatures
• Magnetoelastic and structural properties of azurite Cu3(CO3)2(OH)2 from neutron scattering and muon spin rotation

Cited by in corpus (3)

• Effects of Disorder on the Pressure-Induced Mott Transition in $\kappa$-BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl
• Probing the Mott Physics in $\kappa$-(BEDT-TTF)${}_2$X Salts via Thermal Expansion
• A uniaxial stress capacitive dilatometer for high-resolution thermal expansion and magnetostriction under multiextreme conditions