Bestemmelse af magnetokalorisk effekt ved 3-omega metoden

Christian Schönbeck, Martin Olesen & Adam Lind

Studenteropgave: Semesterprojekt

Abstrakt

This work investigates the magnetocaloric effect in the lanthanium manganite La(0,67)Ca(0,22)Sr(0,11)MnO(3) by means of the so-called 3-omega detection technique. The aim is to determine whether the 3-omega detection technique is suitable for measuring the magnetocaloric effect of certain magnetic materials. An experiment is conducted by subjecting the material to an oscillating magnetic field. The oscillating magnetic field is generated by applying a voltage to a solenoid. By means of Fourier transformation, the third harmonic is extracted from the output voltage. It is concluded that the magnetocaloric effect cannot be detected in the conducted experiment, due to fact that the resulting third harmonic is too small to be measurable. However, an improved experimental design might make it possible to enhance the signal to a measurable level. In this case, the 3-omega detection technique has some advantages compared to the usual techniques used for measuring magnetocaloric effect.

UddannelserFysik, (Bachelor/kandidatuddannelse) Kandidat
SprogDansk
Udgivelsesdato1 jan. 2005
VejledereThomas Schrøder

Emneord

  • 3-omega metoden
  • magnetokalorisk effekt
  • frekvensafhængige målinger
  • Magnetisk køling