scholarly journals Electrical and Magnetic Investigations of Magnesium-doped Epitaxial Gadolinium Nitride Thin Films

2021 ◽  
Author(s):  
◽  
Chang Min Lee
Keyword(s):  
Thin Films ◽  
Magnetic Measurements ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Undoped Film ◽  
Mg Doping ◽  
Insulating Films ◽  
Gadolinium Nitride ◽  
Hall Effect Measurements ◽  
Mg Doped

<p>Mg-doped epitaxial GdN thin films with various Mg-doping levels were grown using molecular beam epitaxy, and their electric, magnetic and optoelectronic properties were investigated. Characterisation through X-ray diffraction technique showed that there is no systematic variation in the crystallographic structure of the films with increasing level of Mg-doping, for Mg concentrations up to ~5 x 10¹⁹ atoms/cm³. However, from Mg concentration ~2 x 10²⁰ atoms/cm³ a clear deterioration in the crystalline quality was seen. We observed an increase in the resistivity of the films from 0.002 Ωcm to 600 Ωcm at room temperature when increasing the Mg-doping level, resulting in semi-insulating films for Mg concentrations up to 5 x 10¹⁹ atoms/cm³. Hall effect measurements revealed that the n-type carrier concentration was reduced from 7 x 10²⁰ cm⁻³ for an undoped film to 5 x 10¹⁵ cm⁻³ for a heavily doped film, demonstrating electron compensation in GdN via Mg-doping. Magnetic measurements exhibited substantial contrasts in the films, with a Curie temperature of ~70 K for an undoped film reduced down to ~50 K for a heavily Mg-doped film. Finally, photoconductivity measurements showed that films with higher level of Mg-doping displaying a faster photoconductive response. The decay time of 13000 s for an undoped film was reduced to 170 s with a moderate level of Mg-doping, which raises the possibility of Mg impurities providing hole traps that act as recombination centres in n-type GdN films.</p>

scholarly journals Electrical and Magnetic Investigations of Magnesium-doped Epitaxial Gadolinium Nitride Thin Films

2021 ◽  
Author(s):  
◽  
Chang Min Lee
Keyword(s):  
Thin Films ◽  
Magnetic Measurements ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Undoped Film ◽  
Mg Doping ◽  
Insulating Films ◽  
Gadolinium Nitride ◽  
Hall Effect Measurements ◽  
Mg Doped

<p>Mg-doped epitaxial GdN thin films with various Mg-doping levels were grown using molecular beam epitaxy, and their electric, magnetic and optoelectronic properties were investigated. Characterisation through X-ray diffraction technique showed that there is no systematic variation in the crystallographic structure of the films with increasing level of Mg-doping, for Mg concentrations up to ~5 x 10¹⁹ atoms/cm³. However, from Mg concentration ~2 x 10²⁰ atoms/cm³ a clear deterioration in the crystalline quality was seen. We observed an increase in the resistivity of the films from 0.002 Ωcm to 600 Ωcm at room temperature when increasing the Mg-doping level, resulting in semi-insulating films for Mg concentrations up to 5 x 10¹⁹ atoms/cm³. Hall effect measurements revealed that the n-type carrier concentration was reduced from 7 x 10²⁰ cm⁻³ for an undoped film to 5 x 10¹⁵ cm⁻³ for a heavily doped film, demonstrating electron compensation in GdN via Mg-doping. Magnetic measurements exhibited substantial contrasts in the films, with a Curie temperature of ~70 K for an undoped film reduced down to ~50 K for a heavily Mg-doped film. Finally, photoconductivity measurements showed that films with higher level of Mg-doping displaying a faster photoconductive response. The decay time of 13000 s for an undoped film was reduced to 170 s with a moderate level of Mg-doping, which raises the possibility of Mg impurities providing hole traps that act as recombination centres in n-type GdN films.</p>

Mg-doped N-polar InN Grown by RF-MBE

2006 ◽  
Vol 955 ◽  
Author(s):  
Daisuke Muto ◽  
Hiroyuki Naoi ◽  
Shinya Takado ◽  
Hyunseok Na ◽  
Tsutomu Araki ◽  
...  
Keyword(s):  
Grain Size ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
X Ray ◽  
Mg Doping ◽  
Surface Migration ◽  
Frequency Plasma ◽  
Growth Properties ◽  
Hall Effect Measurements ◽  
Mg Doped

ABSTRACTWe have investigated the growth properties of Mg-doped N-polar InN films grown by radio-frequency plasma-assisted molecular beam epitaxy (RF-MBE). We found that the Mg-doped InN films had smaller grain size than non-doped films, and furthermore the grain size decreased with an increase in Mg doping amount. Non-doped InN exhibited a single X-ray diffraction (XRD) peak of (0002) h-InN. On the other hand, the Mg-doped InN produced a weak XRD peak of (111) c-InN in addition to a strong peak of (0002) h-InN. These results indicate that the Mg doping decreased the surface migration length of In atoms. From Hall-effect measurements, all the samples were shown to have n-type conductivity. Mg-doped InN grown with Mg cell temperatures of 130 and 135°C had carrier concentrations that were about half (i.e., ∼4.5×1018 cm−3) that of the non-doped InN. However, the carrier concentration tended to increase with further supply of Mg. These results indicate that Mg-doping causes a trade-off between a carrier decreasing effect from the Mg acceptors and a carrier increasing effect from defects caused by the poor surface migration of In atoms.

scholarly journals Structural and Magnetic Properties of FePd Thin Film Synthesized by Electrodeposition Method

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1454
Author(s):  
Gabriele Barrera ◽  
Federico Scaglione ◽  
Matteo Cialone ◽  
Federica Celegato ◽  
Marco Coïsson ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetic Properties ◽  
Deposition Time ◽  
Magnetic Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fundamental Properties ◽  
Magnetic Features ◽  
Application Fields

Bimetallic nanomaterials in the form of thin film constituted by magnetic and noble elements show promising properties in different application fields such as catalysts and magnetic driven applications. In order to tailor the chemical and physical properties of these alloys to meet the applications requirements, it is of great importance scientific interest to study the interplay between properties and morphology, surface properties, microstructure, spatial confinement and magnetic features. In this manuscript, FePd thin films are prepared by electrodeposition which is a versatile and widely used technique. Compositional, morphological, surface and magnetic properties are described as a function of deposition time (i.e., film thickness). Chemical etching in hydrochloric acid was used to enhance the surface roughness and help decoupling crystalline grains with direct consequences on to the magnetic properties. X-ray diffraction, SEM/AFM images, contact angle and magnetic measurements have been carried out with the aim of providing a comprehensive characterisation of the fundamental properties of these bimetallic thin films.

Dielectric and Room Temperature Tunable Properties of Mg-doped Ba0.96Ca0.04Ti0.84Zr0.16O3 Thin Films on Pt/MgO

2002 ◽  
Vol 720 ◽  
Author(s):  
T.S. Kalkur ◽  
Woo-Chul Yi ◽  
Elliott Philofsky ◽  
Lee Kammerdine
Keyword(s):  
Thin Films ◽  
Bottom Electrode ◽  
Dissipation Factor ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
High Tunability ◽  
High Dielectric ◽  
Mgo Substrate ◽  
Mg Doped

AbstractMg- doped Ba0.96 Ca0.04 Ti0.84Zr0.16O3 (BCTZ) thin films were fabricated on Pt/MgO substrate by metallorganic decomposition method. The structure of the films were analyzed by x-ray diffraction. The electrical measurements were performed on metal-ferroelectric-metal capacitors with platinum as the top and bottom electrode. The dielectric properties were improved after the capacitors were post annealed at 700 °C in oxygen atmosphere for 30 min. A high dielectric constant of 504 and a dissipation factor of less than 4% was obtained at 1 MHz. The Pt/BCTZ/Pt/MgO capacitors exhibited high tunability of 55% at an applied field of 55 kV/cm.

The Crystal Structure and Magnetic Property of Bi-Substituted Nd2Fe17-x-yTixSiy Intermetallic Compounds

2014 ◽  
Vol 644-650 ◽  
pp. 4950-4955 ◽  
Author(s):  
Li Mei Sun ◽  
Song Bai Han ◽  
Yun Tao Liu ◽  
Dong Feng Chen ◽  
Xiang Feng Liu
Keyword(s):  
Crystal Structure ◽  
Silicon Content ◽  
Unit Cell Volume ◽  
Magnetic Measurements ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Rietveld Refinements ◽  
X Ray ◽  
Si Content ◽  
Ti Content

The synergetic effects of the substitution of Ti and Si for Fe on the crystallographic structure and magnetic properties of Nd2Fe17-x-yTixSiycompounds have been comprehensively investigated by means of x-ray diffraction, neutron diffraction and magnetic measurements. Rietveld refinements of the diffraction data indicate that all the samples crystallize in the rhombohedral Th2Zn17-type structure. For a given Ti content, thea-axis and the unit cell volumeVof Nd2Fe17-x-yTixSiydecrease linearly with increasing silicon content, while thec-axis behaves complicatedly dependent on different Ti content. The site occupancies of Ti and Si in the crystallographic sites significantly change compared to what is observed in the corresponding singly substituted compounds. TheTCof doubly substituted Nd2Fe16.5-yTi0.8Siyand Nd2Fe16.5-yTi0.5Siyis higher than that of singly substituted Nd2Fe16-ySiyfor a lower Si content while the converse behavior is observed for a higher Si content. For a given Ti content, theTCof Nd2Fe17-x-yTixSiycompounds increases with increasing Si content and theMsfirst increases and then decreases. TheMsof Nd2Fe17-x-yTixSiydecreases with the increase of Ti content.

CRYSTAL STRUCTURE AND PROPERTIES OF CU-AL-O THIN FILMS

2002 ◽  
Vol 16 (01n02) ◽  
pp. 308-313 ◽  
Author(s):  
YUE WANG ◽  
HAO GONG ◽  
LING LIU
Keyword(s):  
Thin Films ◽  
Transparent Conducting Oxide ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Transparent Conducting ◽  
Potential Applications ◽  
Metal Organic ◽  
Hall Effect Measurements ◽  
Organic Precursors ◽  
P Type

P-type transparent conducting oxide thin films have attracted much attention due to their potential applications in novel transparent p-n junction devices. In this work, the transparent conducting Cu-Al-O thin films were prepared by the plasma enhanced chemical vapor deposition using metal organic precursors of Cu(acac) 2 and Al(acac) 3 (acac=acetylacetonate) while the substrate temperature was varied from 700 to 800°C. The x-ray diffraction and SEM results are analyzed to investigate the structure of the as-deposited and annealed films. The films contain metal copper and small grains of CuAlO 2. After annealing, metal copper turned into CuO . Hall effect measurements reveal that these films are p-type semiconductors and the film conductivity increased with the growth temperature.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

Structure-Property Relationship of Ion-Beam Sputtered Nd-Fe-B Magnetic Thin Films On (111) Silicon

1994 ◽  
Vol 354 ◽  
Author(s):  
Anthony S. Nazareth ◽  
Harsh Deep Chopra ◽  
D. K. Sood ◽  
R. B. Zmood
Keyword(s):  
Thin Films ◽  
Ion Beam ◽  
Magnetic Thin Films ◽  
Misfit Strain ◽  
Crystallographic Structure ◽  
Nominal Composition ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Relationship Of

AbstractA focussing grid broad beam Kaufman source, using argon ions on a target of nominal composition Nd2Fei4B has been employed to sputter deposit magnetic thin films of thicknesses ranging from 800 â to 1300 â on silicon-(lll) substrates at room temperature. These films were characterised for their composition depth profile by Rutherford Backscattering Spectroscopy, while x-ray diffraction was used to study the crystallographic structure. Due to a close match between (111) Si with (220) Nd2Fej4B lattice spacings, preferred crystallographic texturing was expected, and experimental results showed a greatly enhanced (220) texture. The degradation in magnetic properties was attributed to the presence of oxygen in the films as indicated by concentration depth profiles. It is premised that another significant role of oxygen may be to relieve the misfit strain across the interface by its incorporation within the Nd2Fej4B phase.

IIIB- Nitride Semiconductors for High Temperature Electronic Applications

1999 ◽  
Vol 572 ◽  
Author(s):  
X. Bai ◽  
D. M. Hill ◽  
M. E. Kordesch
Keyword(s):  
Thin Films ◽  
Nitrogen Pressure ◽  
Atomic Nitrogen ◽  
Nitride Semiconductors ◽  
Infrared Transmission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Evaporation ◽  
Hall Effect Measurements ◽  
High Temperature Electronic

ABSTRACTThin films of ScN and YN were grown on silicon, quartz and sapphire using metal evaporation and an RF atomic nitrogen source. YN decomposes on contact with water vapor, and only AlN capped films could be stabilized. ScN is stable in air and water, and thin films of this material deposited at temperatures between 300 and 900 °C show a substrate-dependent film texture. Typical growth rates were ∼ 0.1 nm/second with a 300W N discharge at about 0.1 mTorr Nitrogen pressure. Structural characterization by x-ray diffraction, infrared transmission spectroscopy and Hall effect measurements on n-type ScN and the fabrication of p-n junctions of n- type ScN with silicon are presented.

The Properties of Dual Acceptor Delta-Doped ZnO Thin Films

2015 ◽  
Vol 1805 ◽  
Author(s):  
T N. Oder ◽  
R.C. Gade ◽  
C. Merlo
Keyword(s):  
Thin Films ◽  
Hole Concentration ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
X Ray Diffraction ◽  
Hall Effect Measurements ◽  
Ceramic Targets ◽  
Post Deposition ◽  
Neutral Acceptor

ABSTRACTWe report the investigation of ZnO thin films delta-doped with lithium and phosphorus introduced simultaneously. The films were deposited from high purity ceramic targets of ZnO and Li3PO4 on c-plane sapphire substrates by RF magnetron sputtering. An undoped ZnO film with a low background electron concentration was used as the buffer layer on the sapphire substrate. The doped films were prepared by carrying simultaneous sputtering from the ZnO and Li3PO4 ceramic targets. For uniform doped films, the simultaneous deposition from the ZnO and Li3PO4 was uninterrupted. For the delta-doped films on the other hand, deposition from the ZnO target was uninterrupted while that from the Li3PO4 was interrupted periodically using a shutter. Post-deposition annealing was carried using a rapid thermal processor in O2 at 900 oC for 3 min. Results obtained from photoluminescence spectroscopy measurements at 12 K revealed acceptor-related luminescence peaks at 3.35 eV, possibly due to the transition from exciton bound to a neutral acceptor. The x-ray diffraction 2θ-scans showed a single peak at about 34.4o. Hall effect measurements revealed p-type conductivities with an average Hall concentrations of 3.8 x 1013 cm-3 in uniform doped samples and 1.5 x 1016 cm-3 in delta doped samples. However, in some cases the Hall coefficients had both positive and negative values, making the determination of the carrier type inconclusive. The fluctuation in the carrier type could be due to the lateral inhomogeneity in the hole concentration caused by signal noise impacting the small Hall voltages in the measurements.

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