SQUID MPMS XL-5

Quantum Design MAGNETOMETR SQUID MPMS XL-5

Alberto M.Testa  -

Sara Laureti  -

Nanostrctured Magnetic Materials Laboratory (nM2-Lab)

 
The RF SQUID - based MPMS s is a fully automated system used to characterize materials when the highest detection sensitivity over a broad temperature range and applied magnetic fields (up to several Tesla) is needed. The RF sQUID device acts as a magnetic flux to voltage converter, detecting the change of magnetic flux created by mechanically moving the sample through a superconducting second order gradiometer pick-up coil (to suppress the influence of all kinds of external magnetic fields); such change is finally converted to a voltage (VSQUID) profile from which the magnetic moment can be unfolded by a fit assuming the dipole approximation.
 
 

TECHNICAL SPECIFICATIONS

  • Superconducting magnet with Hmax max = 5.5 T 
  • Operating range 4K< T < 400K
  • Sensitivity in magnetic moment  :  1 *10-6 emu

AVAILABLE TECHNIQUES

The SQUID control software supports a number of different measurement protocols to evaluate primary magnetic properties(e.g. Ms, Hc, Kan, TC)  and for advanced studies on inter-particle (grain) interactions, aging effects and temperature dependent behavior.

  • Field-dependent Magnetization Loops
  • Remanence Measurements
  • Direct Current Demagnetizing Curves (DCD)
  • isothermal Remanent Measurements (IRM)
  • δM / Henkel plot
  •  
  • Field and zero field cooled
  • TermoRemanence curves
  • Time-dependent Magnetization Measurements
 

SAMPLE

  • Sample dimensions for disks or thin film : 3 x 3 mm (max) 

  • Special sample holders available for powder and liquid samples 

  • Average time duration for an hysteresis loop is approx. 120 min

 

USE FOR

  • Magnetic thin films and heterostructures
  • Magnetic nanoparticles
  • Magnetic nanoarchitectures
  •  Hybrid magnetic nanocomposites
  • Fundamental studies on materials of applicative interest (energy, biomedicine, sensors, environment, information storage, ICT and cultural heritage)
 
 

Case Studies

Magnetic properties of ultra-small CoFe nanoparticles2O4


The magnetic properties of ultra-small (3 nm) CoFe2O4 nanoparticles have been investigated by DC magnetization measurements as a function of temperature and magnetic field. The main features of the magnetic behaviour are blocking of non-interacting particle moments (zero-field-cooled magnetization Tmax ≈ 40 K), a rapid increase of saturation magnetization at low T (up to values higher than for the bulk material) and an increase in anisotropy below 30 K due to the appearance of exchange bias. The low temperature behaviour is determined by a random freezing of surface spins. Localized spin-canting and cation distribution between the two sublattices of the spinel structure account quantitatively for the observed increase in saturation magnetization.
 
D. Peddis et al., Nanotechnology  21, 22341 ( 2010) 125705 ( 2010)

 
 
 

Ferromagnetic Mn-doped Si 0.3 Ge 0.7 nanodots self-assembled on Si(100)
 
LThe magnetic properties of Mn5Ge1Si2 nanocrystallites embedded in Si 0.3 Ge 0.7 nanodots have been investigated by magnetization measurements as a function of temperature and magnetic field. A ferromagnetic behaviour has been observed, with a Curie temperature of approx. 225 K and a value of the critical exponent  = 0.202 indicating a finite-sized two-dimensional (2D) XY layered magnet, with the hysteresis observed at 5K in the XY plane only
 
P. De Padova et al., J. Phys.: Condens. Matter 24 (2012) 142203