Slow magnetic dynamics in the K3M3IIM2IIIF15 multiferroic system

K3Fe5F15 is a multiferroic material belonging to the K3M3IIM2IIIF15 family. Zero-field cooled and field cooled magnetization measured as a function of temperature demonstrate magnetic transition in K3Fe5F15, K3Fe3Cr2F15, and K3Cu3Fe2F15. Complementary to this, the magnetic behavior below the magnetic transition was studied via magnetic relaxation at different temperatures after switching magnetic field from H to −H. A slow change of magnetization on the hours time scale was observed and it was best described by a logarithmic time dependence for all three compounds over a broad temperature and field range. It follows that a distribution of magnetic moments over anisotropy barriers, which block the magnetic moments against reorientation, is present. We introduced a model of thermal activation of the magnetic moments of regions distributed over the barriers to describe the temperature and field dependence of the relaxation parameters. The dimensions of these magnetic regions were estimated to be of nanometer size

Magnetic memory effect in multiferroic K3Fe5F15 and K3Cr2Fe3F15

The fluorides K3Fe5F15 and K3Cr2Fe3F15 are known as multiferroic materials. Here we report the detection of a magnetic memory effect in these materials and its dependence on temperature and aging time. We succeeded in writing, reading, and deleting 3-bits digital information in these systems. These results show that in addition to their already known magneto-electric multiferroic properties, K3Fe5F15 and K3Cr2Fe3F15 also possess a new functionality: they can be used as materials for a thermal memory cell

The influence of public-private partnership upon construction process

As a direct result of efforts for improved quality and efficiency of public services, as well as the efforts to increase insufficient financial resources of the public sector, increased cooperation between public and private sector can be observed in the EU member states. In public-private partnership (PPP), the private partner provides capital means that could not be otherwise ensured by the public sector. In addition, the private partner is encouraged to use construction methods that decrease the project costs and increase its efficiency. The collaborating private sector also takes over operation of the facility over a time period determined by the partnering contract. As a consequence, new fields of activity and business opportunities are opened to the private sector. The thesis presents the main features of public-private partnership and Slovenian and foreign experiences with this procurement method. In particular, the thesis deals with risks associated with such partnerships, and technical aspects, where PPP has numerous advantages when compared to traditional procurement routes. Experiences from different countries show that a successful PPP can lead to use of new construction methods as well as improved facility management, such as partnering and whole life cost analysis