|
Pressure influence on the magnetic and transport properties of the f-electron compounds
Míšek, Martin ; Javorský, Pavel (advisor) ; Kamarád, Jiří (referee)
In this thesis, we describe the work with a new pressure cell, its implementation in Joint Laboratory for Magnetic Studies, together with testing measurements necessary for ensuring good environmental conditions control and trouble-free operation. We have chosen a single crystal of the CePtSn compound to be the first representative measurement. We measured electrical resistivity along crystallographic b-axis in conditions: T = 2-300 K, p = 0-2.5 GPa and magnetic field B = 0-14 T applied along b-axis. We observed only minimal pressure influence on temperatures of magnetic phase transitions, however interesting and rather unusual behavior in magnetic fields was revealed. Previous works reported two field-induced transitions at low temperatures and ambient pressure, with values of the critical fields BcLF ~ 4 T and BcHF ~ 11.5 T, accompanied with large magnetoresistence step of -30% and +10%, respectively. With application of pressure, we observed shift of the critical field of low-field transition BcLF to the higher fields, whereas the value of critical field of high-field transition BcHF was unaffected with applied pressure. At a p ~ 1.5 GPa the two transitions merged and only one step was observed. With pressure further increasing above 1.5 GPa, situation with two transitions, similar to the lower pressure...
|
guest ::
