The Magnetism Competence Center holds 8 tools allowing to realize various physical properties measurements as a function of magnetic field and/or temperature :
Two SQUID magnetometers from "quantum design" (MPMS SQUID and VSM-SQUID) allows to measure small magnetic signals with a resolution less than 10-8 emu. Both are equipped with a superconducting coil 7 T. Control the temperature of the sample can be 5K to 400K and 2K to 1000K respectively. These devices are typically dedicated to the study of magnetic materials including at least one dimension or nano materials bulk / powder of very low magnetization.
On the rigth lays an example of SQUID-VSM (left) measurement that allowed to characterize the Ni impurity within an assembly of carbon nanotubes and check the process of Ni purification (B.Vigolo et al., Team 205: Matériaux carbonés, European Patent Application, PCT/FR2011/052519 (2011)
Three cryostats, equipped with superconducting coils 7 and 9 T (PPMS) from Quantum Design, provide multiple options, partly interchangeable from tool to tool :
This PPMS allows to determine specific heat of magnetocaloric Mn3Sn2 under magnetic field. ( Q. Recour, phD UL, Team 103: Composés intermétalliques et matériaux hybrides. Q. Recour et al., J. Appl. Phys. 105, 033905 (2009))
This PPMS (left) allows to follow the domain wall motion in nanowire (here 500nm diameter) using Hall effect measurement. (Sylvain Legall, Team 101, private communication)
Two vibrating sample magnetometers (from ADE and LakeShore) measure magnetic signals with a resolution of the order of 10-6 emu. The sample can be rotated in magnetic field, manually (LakeShore VSM) and automatically (ADE VSM). Both are equipped with coils that can produce fields of the order of 2.5 Tesla. Finally, the ADE VSM can control the sample temperature with cold or hot nitrogen stream from 100 K to 600 K. These VSMs can accommodate magnetic materials such as single crystal thin film, powder, liquid magnetic.
The 2 VSMs allows measuring the sample magnetic moment both parallel and perpendicular to the field as a function of field amplitude and field direction. Here an exemple of patterned samples, where patterning induces magnetic anisotropy.
To meet the specific demands of users, Stephane Suire develops specific instruments that can be adapted on PPMS cryostats. The development process goes through a personalized study of the need together with the requesting researcher or team.
(left) An insert has been specifically developed to measure the resistance (or Hall effect) of a sample as a function of temperature at various angles of the magnetic field direction. (right) Pneumatic allowing rapid variation of the magnetic field (with a withdrawal speed of 1.5 m / s out of the field) for measuring the magnetocaloric effect.
L’hélium liquide est utilisé à l'IJL dans différents instruments de recherche pour contrôler la température des matériaux et échantillons étudiés et refroidir les bobines supraconductrices permettant de générer des forts champs magnétiques.
Afin de préserver cette ressource rare et chère, un système complet de reliquéfaction de l’hélium permet d’acheminer, de stocker puis de liquéfier de gros volumes de gaz Hélium afin de produire de l’Hélium liquide recyclé.
Les services fournis sont les suivants :
Le liquéfacteur d'hélium fait partie des équipements acquis dans le cadre du projet Tube Daum avec un cofinancement de l'Union Européenne pour un montant total de 7.191.000 €. L'Europe s'engage en région Grand Est avec le Fonds européen de développement régional.