Effect of the growth temperature and nitrogen precursor on the structural and electrical transport properties of SmN thin films

MRS Advances ◽  
2017 ◽  
Vol 2 (3) ◽  
pp. 165-171
Author(s):  
Jay R. Chan ◽  
Mohamed Al Khalfioui ◽  
Stéphane Vézian ◽  
Joe Trodahl ◽  
Benjamin Damilano ◽  
...  

ABSTRACTWe report on the structural and electrical properties of epitaxial SmN thin films grown by molecular beam epitaxy. The effect of the growth temperature and nitrogen precursor, either pure molecular N2 or NH3 was investigated. The structural quality of SmN was assessed by X-ray diffraction and the epitaxial growth character is observed over the entire range of growth temperatures, from 300°C to 800°C, with both nitrogen precursors. The highest quality films are produced at a growth temperature of about 430°C by using N2 as a nitrogen precursor. Hall Effect and resistivity measurements establish that SmN films are heavily n-type doped semiconductors, suggesting the presence of nitrogen vacancies, a recurring phenomenon in rare earth nitride compounds.

2000 ◽  
Vol 639 ◽  
Author(s):  
Feng Yun ◽  
Michael A. Reshchikov ◽  
Paolo Visconti ◽  
Keith M. Jones ◽  
Dongfeng Wang ◽  
...  

ABSTRACTThe structural quality of the buffer layer juxtaposed to the substrate is pivotal in attaining high quality GaN layers. In MBE deposition, low temperature, medium temperature and high temperature AlN buffer layers are at the disposal of the grower. There are quite a few reports, some discussing the benefits of high temperature buffer layers and others doing the same for low temperature buffer layers. The reports emanate from different laboratories; and due to stringent parameter control required, it is difficult to compare one type of buffer with another. To gain some insight, we undertook an investigation wherein these varieties of buffer layers were grown on nitridated sapphire substrate under similar conditions for a comparative analysis. In addition to the single buffer layers of both GaN and AlN varieties, some combinations of stacked buffer layers, including cases where these buffer layers were separated by GaN layers, were employed. Structural analysis by high resolution X-ray diffractometry and topological analysis by AFM were carried out to assess the quality of the epilayers grown on these buffers. Hall measurements at room temperature were carried out to characterize the electrical transport properties.


2018 ◽  
Vol 44 (11) ◽  
pp. 12539-12546 ◽  
Author(s):  
Wenzhe Guo ◽  
Congmian Zhen ◽  
Chunfang Wu ◽  
Xiancheng Wu ◽  
Guoke Li ◽  
...  

2000 ◽  
Vol 622 ◽  
Author(s):  
O. Ambacher ◽  
A. Link ◽  
S. Hackenbuchner ◽  
M. Stutzmann ◽  
R. Dimitrov ◽  
...  

ABSTRACTTwo dimensional hole and electron gases in wurtzite GaN/AlxGa1-xN/GaN heterostructures are induced by strong polarization induced effects. The sheet carrier concentration and the confinement of the two dimensional carrier gases located close to one of the AlGaN/GaN interfaces are sensitive to a high number of different physical properties such as polarity, alloy composition, strain, thickness and doping. We have investigated the structural quality, the carrier concentration profiles and electrical transport properties by a combination of high resolution x- ray diffraction, Hall effect and C-V profiling measurements. The investigated heterostructures with N- and Ga-face polarity were grown by metalorganic vapor phase or plasma induced molecular beam epitaxy covering a broad range of alloy compositions and barrier thickness. By comparison of theoretical and experimental results we demonstrate that the formation of two dimensional hole and electron gases in GaN/AlGaN/GaN heterostructures both rely on the difference of the polarization between the AlGaN and the GaN layer. In addition the role of polarity on the carrier accumulation at different interfaces in n- and p-doped heterostructures will be discussed in detail


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Van Hien-Hoang ◽  
Nak-Kwan Chung ◽  
Heon-Jung Kim

AbstractThe Kondo effect has been a topic of intense study because of its significant contribution to the development of theories and understanding of strongly correlated electron systems. In this work, we show that the Kondo effect is at work in La1−xPrxNiO3−δ (0 ≤ x ≤ 0.6) thin films. At low temperatures, the local magnetic moments of the 3d eg electrons in Ni2+, which form because of oxygen vacancies, interact strongly with itinerant electrons, giving rise to an upturn in resistivity with x ≥ 0.2. Observation of negative magnetoresistance, described by the Khosla and Fisher model, further supports the Kondo picture. This case represents a rare example of the Kondo effect, where Ni2+ acts as an impurity in the background of Ni3+. We suggest that when Ni2+ does not participate in the regular lattice, it provides the local magnetic moments needed to scatter the conduction electrons in the Kondo effect. These results offer insights into emergent transport behaviors in metallic nickelates with mixed Ni3+ and Ni2+ ions, as well as structural disorder.


2001 ◽  
Vol 688 ◽  
Author(s):  
Rasmi R. Das ◽  
W. Pérez ◽  
P. Bhattacharya ◽  
Ram. S. Katiyar

AbstractWe have grown SrBi2Ta2O9 (SBT) thin films on various bottom electrodes such as Pt/TiO2/SiO2/Si (Pt) and LaNiO3/Pt/TiO2/SiO2/Si (LNO) substrates. The substrate temperature and oxygen pressure for the SBT film was maintained at 500 °C and 200 mTorr. As-grown films were post-annealed at a temperature of 800 °C. X-ray diffraction studies revealed that as-grown films were amorphous and crystallized to single phase after annealing. The difficulty of obtaining lowest Raman modes of SBT on platinized silicon substrate was overcome by using conducting oxide electrodes. Films grown on platinized silicon showed maximum value of remanent polarization (2Pr ∼ 21.5 μC/cm2) with coercive field (Ec) of ∼ 67 kV/cm. The degradation of ferroelectric properties of the films was observed with the introduction of 50 nm conducting LaNiO3 electrode at the interface of Pt and SBT film, which was attributed to high resistivity of the oxide electrode layers. Leakage current density was studied with the consideration of the Schottky emission model. The barrier height of the films grown on Pt and LNO were estimated to be 1.27 eV and 1.12 eV, respectively. The reduction of barrier height was attributed to the lower work function of the LNO electrode.


1994 ◽  
Vol 339 ◽  
Author(s):  
T. J. Kistenmacher ◽  
S. A. Ecelberger ◽  
W. A. Bryden

ABSTRACTIntroduction of a buffer layer to facilitate heteroepitaxy in thin films of the Group IIIA nitrides has had a tremendous impact on growth morphology and electrical transport. While AIN- and self-seeded growth of GaN has captured the majority of attention, the use of AIN-buffered substrates for InN thin films has also had considerable success. Herein, the properties of InN thin films grown by reactive magnetron sputtering on AIN-buffered (00.1) sapphire and (111) silicon are presented and, in particular, the evolution of the structural and electrical transport properties as a function of buffer layer sputter time (corresponding to thicknesses from ∼50Å to ∼0.64 μm) described. Pertinent results include: (a) for the InN overlayer, structural coherence and homogeneous strain normal to the (00.1) growth plane are highly dependent on the thickness of the AIN-buffer layer; (b) the homogeneous strain in the AIN-buffer layer is virtually nonexistent from a thickness of 200Å (where a significant X-ray intensity for (00.2)AIN is observed); and (c) the n-type electrical mobility for films on AIN-nucleated (00.1) sapphire is independent of AIN-buffer layer thickness, owing to divergent variations in carrier concentration and film resistivity. These effects are in the main interpreted as arising from a competition between the lattice mismatch of the InN overlayer with the substrate and with the AIN-buffer layer.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. Jantayod ◽  
D. Doonyapisut ◽  
T. Eknapakul ◽  
M. F. Smith ◽  
W. Meevasana

Abstract The electrical transport properties of a thin film of the diamondoid adamantane, deposited on an Au/W substrate, were investigated experimentally. The current I, in applied potential V, from the admantane-thiol/metal heterstructure to a wire lead on its surface exhibited non-symmetric (diode-like) characteristics and a signature of resistive switching (RS), an effect that is valuable to non-volatile memory applications. I(V) follows a hysteresis curve that passes twice through $$I(0)=0$$ I ( 0 ) = 0 linearly, indicating RS between two states with significantly different conductances, possibly due to an exotic mechanism.


2021 ◽  
pp. 100113
Author(s):  
Jyoti Yadav ◽  
Rini Singh ◽  
M.D. Anoop ◽  
Nisha Yadav ◽  
N. Srinivasa Rao ◽  
...  

2022 ◽  
Vol 64 (3) ◽  
pp. 326
Author(s):  
С.А. Кукушкин ◽  
А.В. Осипов ◽  
Е.В. Осипова ◽  
В.М. Стожаров

X-ray diffraction and total external reflection of X-rays (X-ray reflectometry) methods were used to study the successive stages of synthesis of epitaxial SiC films on Si (100) X-ray diffraction and total external X-ray reflection (XRD) methods were used to study successive stages of synthesis of epitaxial SiC films on Si (100) surfaces, (110) and (111) surfaces by the atom substitution method. The data on the transformation evolution of (100) surfaces were studied, (110) and (111) Si, into SiC surfaces. A comparative analysis of the X-ray structural quality of the SiC layers grown on Si by the atom substitution method with the quality of SiC layers grown by Advanced Epi by the standard CVD method. A modified technique for the total outer X-ray reflection method, based on measurements of the intensity of the reflected X-rays using a special parabolic mirror. It is shown that the method of total external reflection method makes it possible to obtain important information about the degree of surface roughness of SiC layers, the evolution of their crystal structure and plasmon energy in the process of Si to SiC conversion.


2016 ◽  
Vol 55 (4S) ◽  
pp. 04EJ08
Author(s):  
Akihiro Tsuruta ◽  
Yusuke Tsujioka ◽  
Yutaka Yoshida ◽  
Ichiro Terasaki ◽  
Norimitsu Murayama ◽  
...  

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