Welcome to the Department of Physics at IMFM -

Laboratory for NQR and weak magnetic fields

Our research is directed towards studies of magnetism and it spans from magnetism in condensed matter physics to magnetism in living state - biomagnetism. Cryophysics and cryotechnology are also parts of our interest. We are active in basic research as well as in applied research.

Research of magnetic properties in condensed matter physics

The research of magnetic properties in condensed matter physics in its broadest sense is an important part of research in physics. It is one of the earlier methods of research in solids. The results of basic research have reached here exceptionally high number of applications and this tendency is present still today. The new nanomaterials are often characterized with interesting magnetic properties and a large variety of applications are expected, spanning from humane health care to defense purposes. Expansions in magnetochemistry and magnetic research in biology is expected in Ljubljana.

Several institutions in Slovenia are active in the above mentioned research. The traditional research in nuclear magnetism (NMR, NQR, EPR) in Ljubjana was complemented by a home built SQUID magnetometer about 10 years ago. Its measuring capacity soon appeared to be too small and we recently purchased a new Magnetic Properties Measuring System MPMS-XL-5 (Quantum Design, San Diego, USA) with improved sensitivity and user friendly automated measuring software. It contains facilities for the dc and ac magnetization measurements as a function of temperature and applied magnetic field; zero field and sample rotation option is available. This way a high quality magnetic measuring system is added and we can easily cover the growing magnetic research needs.

In order to achieve better efficiency of this powerful equipment we established an association of several research institutions, called the Center for Magnetic measurements - CMag. Present members are;

CMag is open for new national and international partners according to the rules of the center.

A heat capacity measuring system, working in the low temperature region (4K-30K) was recently added.

NQR research

Nuclear Quadrupole Resonance (NQR) with its ability of identification specific molecules in measured sample is potentially powerful method in solid state physics, chemistry and pharmacy. NQR data can be used to get additional information on molecular and crystal structure, on lattice dynamics, on chemical bond character, for nondestructive characterization of some solid chemical compounds, etc. The NQR spectroscopy is a good supplement to NMR and EPR spectroscopy. Sharp, orientation independent NQR lines can be obtained using either powder samples or single crystals. In NQR it is the interaction of nuclear quadrupole moment with the electric field gradient at the site of the nucleus (the intrinsic crystal field caused by the intra- and interatomic electric fields) which determines the energy splitting of nuclear quantum states. The rf magnetic field is the only external field, necessary to excite the quadrupole transitions. Additional external (quasi)static magnetic or electric field may be applied only to get more information. Drawback of the pure NQR method is that relatively large number of chemically equivalent quadrupole nuclei is needed (approx. 1019) to obtain sufficient S/N ratio.

Some subjects of our interest are:

Measurements of biomagnetic signals

Main experimental instrumentation:


Cryophysics has been an accompanying part of our research activities practically from the beginning. However, with the applications of SQUID sensor it became more important one and now it can be divided in two parts:

Applied physics

Various contributions to applied research came from our group in the last 20 years, like:

[Members] [Projects] [Conferences] [Bibliography] [IMFM]
[Department of Physics - HOME]