Author of thesis: Ing. Kateřina Fabianová
Acad. year: 2017/2018
Supervisor: Ing. Vojtěch Uhlíř, Ph.D.
Reviewer: doc. Mgr. Adam Dubroka, Ph.D.
Abstract:Iron-rhodium (FeRh) is a material undergoing a first order magnetic phase transition from antiferromagnetic (AF) to ferromagnetic (FM) phase which occurs when the material is heated above the transition temperature or by applying a sufficiently large magnetic field. This phase transition is accompanied by a significant change in entropy, magnetization and electric resistivity while the transition temperature is strongly dependent on the crystal stoichiometry, elemental substitution, pressure and in case of thin layers on the strain induced by the substrate.
This work is focused on the study of magnetotransport properties of wires patterned from FeRh thin layers grown on substrates inducing different strain in the layer. One of the main effects studied in this work is the anisotropic magnetoresistance (AMR) demonstrated by a change of the resistance for different orientations of the magnetic moments in the material with respect to the electric current direction. The AMR was studied both in the FM and AF phase of FeRh. The AMR of the FM phase in the high temperature phase was measured and an unexpected behavior of the AMR of the residual FM phase of FeRh in the low temperature phase was discovered. A strong dependence of the AMR on the orientation of the measured segment with respect to the crystallographic directions of FeRh was explored.
iron-rhodium, phase transition, antiferromagnet, ferromagnet, transport measurement, anisotropic magnetoresistance
Date of defence
18.06.2018
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Je vrstva FeRh skutečně monokrystal? Jak byste se o tom přesvědčila? Jak se dá zbavit zbytkové feromagnetické fáze na rozhraní substrátu a FeRh? Jakou tloušťku mají vámi připravené monokrystaly? Proč definujete AMR pomocí kvadrátu funkce cosinus a ne součtem funkcí kosinus a sinus?
Language of thesis
English
Faculty
Department
Study programme
Applied Sciences in Engineering (M2A-P)
Field of study
Physical Engineering and Nanotechnology (M-FIN)
Composition of Committee
prof. RNDr. Tomáš Šikola, CSc. (předseda)
prof. RNDr. Miroslav Liška, DrSc. (místopředseda)
prof. RNDr. Bohumila Lencová, CSc. (člen)
prof. RNDr. Jiří Komrska, CSc. (člen)
prof. RNDr. Petr Dub, CSc. (člen)
prof. RNDr. Radim Chmelík, Ph.D. (člen)
prof. RNDr. Jiří Spousta, Ph.D. (člen)
prof. RNDr. Eduard Schmidt, CSc. (člen)
prof. RNDr. Pavel Zemánek, Ph.D. (člen)
RNDr. Antonín Fejfar, CSc. (člen)
doc. Ing. Radek Kalousek, Ph.D. (člen)
Supervisor’s report
Ing. Vojtěch Uhlíř, Ph.D.
Grade proposed by supervisor: A
Reviewer’s report
doc. Mgr. Adam Dubroka, Ph.D.
Grade proposed by reviewer: A