Neutron imaging of liquid-liquid systems containing paramagnetic salt solutions

Abstract

The method of neutron imaging was adopted to map the concentration evolution of aqueous paramagnetic Gd(NO3)3 solutions. Magnetic manipulation of the paramagnetic liquid within a miscible nonmagnetic liquid is possible by countering density-difference driven convection. The formation of salt fingers caused by double-diffusive convection in a liquid-liquid system of Gd(NO3)3 and Y(NO3)3 solutions can be prevented by the magnetic field gradient force.

Neutron Imaging of Paramagnetic Ions: Electrosorption by Carbon Aerogels and Macroscopic Magnetic Forces

“…This was low enough to avoid the high absorption limit, where the transmittance is dominated by scattering, while retaining the Gd 3+ concentration for the paramagnetic susceptibility. 6 …”

“…It allows magnetic levitation of submerged objects 3 , 4 or the inhibition of density-difference-driven convection. 5 , 6 The latter is of particular interest since it follows that paramagnetic liquids can be manipulated in non-magnetic miscible liquids. The magnetically modified concentration profile is eventually homogenized by diffusion.…”

“…7 − 9 After a 50 year hiatus, interest in the effects of magnetic field gradients on ionic solutions has been revived. 5 , 6 , 10 − 23 Magneto-convection only arises when the magnetic field gradient force is rotational, which necessitates a susceptibility gradient and magnetic field gradient that are non-parallel. 24 Interferometric measurements generated evidence of magnetic ion enrichment around the surface of an evaporating solution containing a single paramagnetic species.…”

Neutron Imaging of Paramagnetic Ions: Electrosorption by Carbon Aerogels and Macroscopic Magnetic Forces

“…1(a) for an example with Gd 3+ ions in the stray field of a permanent magnet). It allows magnetic levitation of submerged objects [3,4] or the inhibition of density-difference driven convection [5,6]. The latter is of particular interest, since it follows that paramagnetic liquids can be manipulated in nonmagnetic miscible liquids.…”

“…Nevertheless, attempts of rare earth ion separation in an inhomogeneous magnetic field were reported by Ida and Walter Noddack in the 1950s [7][8][9]. After a 50 year hiatus, interest in the effects of magnetic field gradients on ionic solutions has been revived [5,6,[10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Magneto-convection only arises when the magnetic field gradient force is rotational, which necessitates a susceptibility gradient and magnetic field gradient that are orthogonal to each other [24].…”