Nickel vertical posts: Influence of thickness on magnetic and optical properties
Апстракт
In the present study we have investigated the influence of the nickel (Ni) thin films thicknesses on their structural, magnetic and optical properties. Nickel vertical posts were deposited by Glancing Angle Deposition technique, at the angle of 85o .The films were grown to the thicknesses of 50 nm, 80 nm, 110 nm and 140 nm onto the glass slide substrates, which were rotated at the constant rate during the deposition process. After the deposition, the samples were characterized by Scanning ElectronMicroscopy (SEM) and it was found that the thin films are porous and that the diameter of the columns increases from 18 nm to 29 nm with increasing thickness.X-ray photoelectron spectroscopy was used in order to determine the chemical composition of the samples, as well as the identification of the compounds present in the deposited thin films. It was shown that the metallic Ni is the dominant component, while the deconvolution of the oxygen line revealed the presence of NiO and Ni(OH)2. Magne...tic measurements of Ni thin films were accomplished by Magneto-Optical Kerr effect Microscope at room temperature. Based on the obtained results it can be seen that the deposited nickel samples possess uniaxial magnetic anisotropy. Also, it was noticed that the coercivity increases with thickness up to 150 Oe, for the 110 nm thick sample and then decreases to the value of 115 Oe. For thinner films, magnetic properties are mainly affected by the diameter of the columns, while for the thicker samples, the mechanism of the column growth determines their characteristics. Optical and electrical properties of nanostructured nickel thin films were investigated by spectroscopic ellipsometry and four-point probe, respectively. According to the ellipsometric measurementsit was found that as the thickness of the deposited samples increases plasma frequency (ωp) also increases, and the damping factor (Γd) decreases. An increase in the plasma frequency means that the density of conducting electrons is higher forthe thicker samples, while the decrease in Γd indicates their better structural arrangement and lower concentration of defects.From the ellipsometric measurements, also, was observed the decrease of the refractive index values with increasing the film thickness, which is due to the lower optical density of the samples. Besides, higher values of the column width of the thicker Ni films lead to the reduced scattering of the conduction electrons at their boundaries and consequently increase both conductivity and extinction coefficient. Indeed, four-point probe measurements revealed that the electrical resistivity decreases from 4.98102μΩcm to 0.44102μΩcm, with increase film thickness from 50 nm to 140 nm. Lower values of electrical resistivity are probably due to the larger column diameter and lower defects density, as a result of column connecting during the film growth.
Извор:
PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade, 2021, 79-Издавач:
- Belgrade : Institute of Physics Belgrade
Напомена:
- VIII International School and Conference on Photonics and HEMMAGINERO workshop : PHOTONICA2021 : book of abstracts; August 23-27, 2021; Belgrade
Институција/група
VinčaTY - CONF AU - Potočnik, Jelena AU - Popović, M. PY - 2021 UR - https://vinar.vin.bg.ac.rs/handle/123456789/10904 AB - In the present study we have investigated the influence of the nickel (Ni) thin films thicknesses on their structural, magnetic and optical properties. Nickel vertical posts were deposited by Glancing Angle Deposition technique, at the angle of 85o .The films were grown to the thicknesses of 50 nm, 80 nm, 110 nm and 140 nm onto the glass slide substrates, which were rotated at the constant rate during the deposition process. After the deposition, the samples were characterized by Scanning ElectronMicroscopy (SEM) and it was found that the thin films are porous and that the diameter of the columns increases from 18 nm to 29 nm with increasing thickness.X-ray photoelectron spectroscopy was used in order to determine the chemical composition of the samples, as well as the identification of the compounds present in the deposited thin films. It was shown that the metallic Ni is the dominant component, while the deconvolution of the oxygen line revealed the presence of NiO and Ni(OH)2. Magnetic measurements of Ni thin films were accomplished by Magneto-Optical Kerr effect Microscope at room temperature. Based on the obtained results it can be seen that the deposited nickel samples possess uniaxial magnetic anisotropy. Also, it was noticed that the coercivity increases with thickness up to 150 Oe, for the 110 nm thick sample and then decreases to the value of 115 Oe. For thinner films, magnetic properties are mainly affected by the diameter of the columns, while for the thicker samples, the mechanism of the column growth determines their characteristics. Optical and electrical properties of nanostructured nickel thin films were investigated by spectroscopic ellipsometry and four-point probe, respectively. According to the ellipsometric measurementsit was found that as the thickness of the deposited samples increases plasma frequency (ωp) also increases, and the damping factor (Γd) decreases. An increase in the plasma frequency means that the density of conducting electrons is higher forthe thicker samples, while the decrease in Γd indicates their better structural arrangement and lower concentration of defects.From the ellipsometric measurements, also, was observed the decrease of the refractive index values with increasing the film thickness, which is due to the lower optical density of the samples. Besides, higher values of the column width of the thicker Ni films lead to the reduced scattering of the conduction electrons at their boundaries and consequently increase both conductivity and extinction coefficient. Indeed, four-point probe measurements revealed that the electrical resistivity decreases from 4.98102μΩcm to 0.44102μΩcm, with increase film thickness from 50 nm to 140 nm. Lower values of electrical resistivity are probably due to the larger column diameter and lower defects density, as a result of column connecting during the film growth. PB - Belgrade : Institute of Physics Belgrade C3 - PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade T1 - Nickel vertical posts: Influence of thickness on magnetic and optical properties SP - 79 UR - https://hdl.handle.net/21.15107/rcub_vinar_10904 ER -
@conference{ author = "Potočnik, Jelena and Popović, M.", year = "2021", abstract = "In the present study we have investigated the influence of the nickel (Ni) thin films thicknesses on their structural, magnetic and optical properties. Nickel vertical posts were deposited by Glancing Angle Deposition technique, at the angle of 85o .The films were grown to the thicknesses of 50 nm, 80 nm, 110 nm and 140 nm onto the glass slide substrates, which were rotated at the constant rate during the deposition process. After the deposition, the samples were characterized by Scanning ElectronMicroscopy (SEM) and it was found that the thin films are porous and that the diameter of the columns increases from 18 nm to 29 nm with increasing thickness.X-ray photoelectron spectroscopy was used in order to determine the chemical composition of the samples, as well as the identification of the compounds present in the deposited thin films. It was shown that the metallic Ni is the dominant component, while the deconvolution of the oxygen line revealed the presence of NiO and Ni(OH)2. Magnetic measurements of Ni thin films were accomplished by Magneto-Optical Kerr effect Microscope at room temperature. Based on the obtained results it can be seen that the deposited nickel samples possess uniaxial magnetic anisotropy. Also, it was noticed that the coercivity increases with thickness up to 150 Oe, for the 110 nm thick sample and then decreases to the value of 115 Oe. For thinner films, magnetic properties are mainly affected by the diameter of the columns, while for the thicker samples, the mechanism of the column growth determines their characteristics. Optical and electrical properties of nanostructured nickel thin films were investigated by spectroscopic ellipsometry and four-point probe, respectively. According to the ellipsometric measurementsit was found that as the thickness of the deposited samples increases plasma frequency (ωp) also increases, and the damping factor (Γd) decreases. An increase in the plasma frequency means that the density of conducting electrons is higher forthe thicker samples, while the decrease in Γd indicates their better structural arrangement and lower concentration of defects.From the ellipsometric measurements, also, was observed the decrease of the refractive index values with increasing the film thickness, which is due to the lower optical density of the samples. Besides, higher values of the column width of the thicker Ni films lead to the reduced scattering of the conduction electrons at their boundaries and consequently increase both conductivity and extinction coefficient. Indeed, four-point probe measurements revealed that the electrical resistivity decreases from 4.98102μΩcm to 0.44102μΩcm, with increase film thickness from 50 nm to 140 nm. Lower values of electrical resistivity are probably due to the larger column diameter and lower defects density, as a result of column connecting during the film growth.", publisher = "Belgrade : Institute of Physics Belgrade", journal = "PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade", title = "Nickel vertical posts: Influence of thickness on magnetic and optical properties", pages = "79", url = "https://hdl.handle.net/21.15107/rcub_vinar_10904" }
Potočnik, J.,& Popović, M.. (2021). Nickel vertical posts: Influence of thickness on magnetic and optical properties. in PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade Belgrade : Institute of Physics Belgrade., 79. https://hdl.handle.net/21.15107/rcub_vinar_10904
Potočnik J, Popović M. Nickel vertical posts: Influence of thickness on magnetic and optical properties. in PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade. 2021;:79. https://hdl.handle.net/21.15107/rcub_vinar_10904 .
Potočnik, Jelena, Popović, M., "Nickel vertical posts: Influence of thickness on magnetic and optical properties" in PHOTONICA2021 : 8th International School and Conference on Photonics and HEMMAGINERO workshop : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 23-27, 2021; Belgrade (2021):79, https://hdl.handle.net/21.15107/rcub_vinar_10904 .