Infrastructure of Thin Films Division in IMP Hubert Głowiński and Janusz Dubowik, IFM PAN
Outline VNA-FMR FMR PIMM Dynamic measurements VSM PPMS MOKE Static measurements GIXRD XRF Structural characterization
Field sweep FMR During field sweep FMR experiment magnetization vector changes its direction
FMR X-band spectrometer 9.18 GHz Field up to 11 kOe Gaussmeter Lock-in Microwave bridge Field sweep controller X-band spectrometer 9.18 GHz Field up to 11 kOe
External magnetic field VNA-FMR Port 1 Port 2 Próbka External magnetic field Microwave field On frequency sweep FMR experiment magnetization vector does not change its direction Impedancja 50 Ω. Frequency up to 40 GHz Coplanar waveguide 5
CPW – coplanar waveguide External magnetic field Magnetic field lines Magnetic field lines Electric field lines Electric field lines Simulated current Homogenous current I. Neudecker et al. JMMM 307 (2006) 148–156
Channelized Coplanar Waveguide The vias are acting as a microwave wall The other determining factor in the high frequency performance of the vias is the spacing between the rows of the vias. The wider the spacing, the lower the cutoff frequency and the closer the spacing the higher the cutoff frequency. http://mpd.southwestmicrowave.com/pdf/Launch_Report.pdf
VNA-FMR Gaussmeter VNA Helmholtz’s coils Power supply
VNA-FMR Frequency sweep mode Different fields Field sweep mode Different frequencies Si Ti Au Co
Pulsed inductive microwave magnetometer (PIMM) Port Port Pulse generator Trigger Sampling oscilloscope Pulse magnetic field Bandwidth 20 GHz Pulse risetime 55 ps Pulse amplitude 10 V Sample External magnetic field
PIMM Pulse generator Oscilloscope Helmholtz coils Power supply
Vibrating Sample Magnetometer – VSM Generator Frequency: 35 Hz Dual pickup coils Magnetic field: up to 16 kOe Temperature: -100oC to 250oC Loudspeaker Glass pipe Gaussmeter Hallotron PC Power supply Pickup coils Lock-in M.Matczak, Thesis, Politechnika Poznańska, Poznań, 2011
PHYSICAL PROPERTY MEASUREMENT SYSTEM (PPMS) Options VSM Resistance Torque magnetometer PPMS system properties: Temperature range: 2 K - 350 K. Magnetic field: up to 9 tesla. Magnetic field ramp rate: determined by magnet and power supply. Temperature and magnetic field may be ramped during the measurement. Pomiar w zależnosci od temperatury i pola oraz kąta (dla oporu)
MOKE Stepper motor Elektromagnet PC Wavelength λ=640 nm Z axis Gaussmeter Power supply Detector Lens Mirror Modulator Analyzer Lock-in Polarizer Laser Z axis Wavelength λ=640 nm M.Matczak, Thesis, Politechnika Poznańska, Poznań, 2011
MOKE – device setup Laser diode Polarizer Modulator Lens Electromagnet Sample holder and table Mirror Analyser Detector (fotodiode) Magnetic field sensor M.Matczak, Thesis, Politechnika Poznańska, Poznań, 2011
MOKE Si Ti Au Co
XRF We can measure: Thickness of thin films (up to 200 nm) Characteristic radiation Multichannel analyzer 10 keV / 1024 channels We can measure: Thickness of thin films (up to 200 nm) Chemical elements composition 1 – X-ray source, 2 - collimator, 3 – sample holder, 4 - detector K. Załęski, Masters thesis, UAM Wydział Fizyki, Poznań 2007 Wikipedia
GIXRD 2θ varies 0o - 10o Seifert, model XRD 3003, X-ray source sample detector aperture 2θ varies 0o - 10o Seifert, model XRD 3003, X-ray source Cu-K (wavelength λ=0.15419 nm) Interference of the wave reflected from surface of the film and the surface of the substrate results in Kiessiga fringes. Allows to measure thickness of thin films P. Kuświk, PhD dissertation, IFM PAN, Poznań, 2010
Summary We are able to characterize magnetically samples (effective fields, anisotropy, damping parameter) We are able to characterize structure of the sample (film thickness, sublayer thickness, chemical composition)
Thank you for your attention! From our data, both F/AF coupling effects, rotatable and unidirectional anisotropy, can be interpreted as unstable AF grain magnetization, just differing by deviating relaxation times. A continuous transition from rotatable to dominating unidirectional anisotropy is observed. 20