17:45 〜 18:00
▼ [15p-501-17] Spin Hall magnetoresistance in Erbium Iron Garnet/Platinum systems
キーワード：Spin Hall magnetoresistance, Iron garnet, Thin film
The spin Hall magnetoresistance (SMR) in erbium iron garnet (ErIG)/platinum (Pt) hybrid systems was investigated in our work. Er3Fe5O12 (ErIG) is a ferrimagnetic material with rich magnetic phases such as the spin canting, spin-reorientation and magnetic compensation temperature due to the weak exchange coupling of the Er-sublattice and Fe-sublattice described as an exchange enhanced paramagnetic state. The aim of our work is to study the influence of the appearance of these phases on the SMR.
To investigate the SMR in ErIG/Pt hybrid systems, we fabricated ErIG/Pt samples by using pulsed laser deposition (PLD) and electron beam evaporator (EVAP). Two different (100)-oriented substrates Y3Al5O12 (YAG) and Gd3Ga5O12 (GGG) were used. YAG was chosen as a substrate to induce strain in the thin ErIG layer due to the large lattice mismatch of around 3%, while the lattice mismatch of GGG and ErIG is only 0.2% resulting in a pseudomorphic growth of thick ErIG layers. The structural and magnetic properties were examined by means of X-ray diffractometry (XRD) and SQUID magnetometry. The fabrication of high quality bilayer systems was confirmed in this process.
Angle-dependent magnetoresistance (ADMR) measurements were carried out to investigate the SMR behavior of the fabricated ErIG/Pt hybrid systems. To this end the ErIG/Pt bilayers were patterned into a Hall bar mesa-structure by optical lithography and argon ion beam milling, then placed in a magnetic cryostat. The sample was rotated in an external magnetic field with a constant magnitude, while the longitudinal and transversal voltages were recorded with respect to the applied electrical current of 100μA. These ADMR measurements were performed within a temperature range of 5 K to 300 K and under a constant magnetic field strength of 1 T to 7 T using three different rotation planes of the magnetic field. The ADMR signals of all ErIG/Pt samples showed typical SMR behavior which can be described by the single domain SMR model using a macro-spin approximation above 100K, above the magnetic compensation temperature Tcomp. Unique features of each sample appeared around the compensation temperature Tcomp exhibiting a strong dependence on the magnetic field strength, the temperature and the thickness of the ErIG layer as well as the substrate material. The effect of magnetic anisotropy became larger at low temperatures below Tcomp.
In conclusion, the resistivity of the Pt layer of different ErIG/Pt samples showed a complicated and rich angle-dependence which can be partially explained by the sublattice SMR model.
To investigate the SMR in ErIG/Pt hybrid systems, we fabricated ErIG/Pt samples by using pulsed laser deposition (PLD) and electron beam evaporator (EVAP). Two different (100)-oriented substrates Y3Al5O12 (YAG) and Gd3Ga5O12 (GGG) were used. YAG was chosen as a substrate to induce strain in the thin ErIG layer due to the large lattice mismatch of around 3%, while the lattice mismatch of GGG and ErIG is only 0.2% resulting in a pseudomorphic growth of thick ErIG layers. The structural and magnetic properties were examined by means of X-ray diffractometry (XRD) and SQUID magnetometry. The fabrication of high quality bilayer systems was confirmed in this process.
Angle-dependent magnetoresistance (ADMR) measurements were carried out to investigate the SMR behavior of the fabricated ErIG/Pt hybrid systems. To this end the ErIG/Pt bilayers were patterned into a Hall bar mesa-structure by optical lithography and argon ion beam milling, then placed in a magnetic cryostat. The sample was rotated in an external magnetic field with a constant magnitude, while the longitudinal and transversal voltages were recorded with respect to the applied electrical current of 100μA. These ADMR measurements were performed within a temperature range of 5 K to 300 K and under a constant magnetic field strength of 1 T to 7 T using three different rotation planes of the magnetic field. The ADMR signals of all ErIG/Pt samples showed typical SMR behavior which can be described by the single domain SMR model using a macro-spin approximation above 100K, above the magnetic compensation temperature Tcomp. Unique features of each sample appeared around the compensation temperature Tcomp exhibiting a strong dependence on the magnetic field strength, the temperature and the thickness of the ErIG layer as well as the substrate material. The effect of magnetic anisotropy became larger at low temperatures below Tcomp.
In conclusion, the resistivity of the Pt layer of different ErIG/Pt samples showed a complicated and rich angle-dependence which can be partially explained by the sublattice SMR model.