scholarly journals N+ Irradiation and Substrate-Induced Variability in the Metamagnetic Phase Transition of FeRh Films

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 661
Author(s):  
Steven P. Bennett ◽  
Samuel W. LaGasse ◽  
Marc Currie ◽  
Olaf Van’t Erve ◽  
Joseph C. Prestigiacomo ◽  
...  

Metamagnetic FeRh has been the focus of numerous studies for its highly unique antiferromagnetic (AF) to ferromagnetic (FM) metamagnetic transition. While this phase transition usually occurs above room temperature (often Tc > 400 K), both ion irradiation and strained epitaxial growth have been used to bring it to applicable temperatures. Nevertheless, cross sample variability is pervasive in these studies. Here we explore the optical and magnetic properties of 35 nm thick FeRh grown by magnetron sputter deposition simultaneously on two different single crystal substrates: epitaxially on MgO (001) and highly strained with large lattice mismatch on Al2O3 (1000). We then irradiate the epitaxial film with 5 keV N+ ions to introduce disorder (and to a lesser extent, modify chemical composition) without effecting the surface morphology. We find that the phase-transitional properties of both films are strikingly different due to the large lattice mismatch, despite being grown in tandem with nominally identical growth conditions including Fe/Rh stoichiometry, pressure, and temperature. We observe that N+ implantation lowers Tc by ~60 K, yielding a sample with nominally the same transition temperature as the non-epitaxial film on sapphire, yet with a significantly increased magnetic moment, a larger magnetization change and a more abrupt transition profile. We attribute these differences to the Volmer-Weber type growth mode induced by the sapphire substrate and the resulting rougher surface morphology.

1985 ◽  
Vol 47 ◽  
Author(s):  
M. C. Tamargo ◽  
R. Hull ◽  
L. H. Greene ◽  
J. R. Hayes ◽  
N. Tabatabaie ◽  
...  

ABSTRACTThin alternating layers of InAs and GaAs have been grown by MBE on buffer layers lattice matched to InP. The layer structure was evaluated by transmission electron microscopy (TEM) and low angle X-ray scattering. Commensurate epitaxial layers approximately 15Å thick were obtained in spite of the large lattice mismatch (7%). These results and their implication for growth conditions of strained-layer superlattices will be discussed.


1989 ◽  
Vol 160 ◽  
Author(s):  
R. Rousina ◽  
J.B. Webb ◽  
J.P. Noad

AbstractThis work reports for the first time, the epitaxial deposition of ln1-xGaxSb on (100)GaAs by Metalorganic Magnetron Sputtering. High quality films could be deposited on GaAs over the entire compositional range despite the large lattice mismatch between the film and substrate (14.6% for InSb and 7.8% for GaSb). The composition of the layers was found to be directly related to the trimethylgallium and trimethylindium fluxes at constant growth temperature. Growth rates of 1 µm/hr for the GaSb and 3 µm/hr for the InSb were observed.


2021 ◽  
Author(s):  
Mingming Jiang ◽  
Yang Liu ◽  
Ruiming Dai ◽  
Kai Tang ◽  
Peng Wan ◽  
...  

Suffering from the indirect band gap, low carrier mobility, and large lattice mismatch with other semiconductor materials, one of the current challenges in Si-based materials and structures is to prepare...


1987 ◽  
Vol 102 ◽  
Author(s):  
D. L. Doering ◽  
F. S. Ohuchi ◽  
W. Jaegermann ◽  
B. A. Parkinson

ABSTRACTThe growth of copper, silver and gold thin films on tungsten disulfide has been examined as a model of metal contacts on a layered semiconductor. All three metals were found to grow epitaxially on the WS2. However, Cu appears to form a discontinuous film while Au and Ag grow layer by layer. Such epitaxial growth is somewhat surprising since there is a large lattice mismatch between the metals and the WS2.


1991 ◽  
Vol 4 (6) ◽  
pp. 217-219 ◽  
Author(s):  
S. Aboulhouda ◽  
J. P. Vilcot ◽  
M. Razeghi ◽  
D. Decoster ◽  
M. Francois ◽  
...  

2002 ◽  
Vol 737 ◽  
Author(s):  
E. Ertekin ◽  
P.A. Greaney ◽  
T. D. Sands ◽  
D. C. Chrzan

ABSTRACTThe quality of lattice-mismatched semiconductor heterojunctions is often limited by the presence of misfit dislocations. Nanowire geometries offer the promise of creating highly mismatched, yet dislocation free heterojunctions. A simple model, based upon the critical thickness model of Matthews and Blakeslee for misfit dislocation formation in planar heterostructures, illustrates that there exists a critical nanowire radius for which a coherent heterostructured nanowire system is unstable with respect to the formation of misfit dislocations. The model indicates that within the nanowire geometry, it should be possible to create perfect heterojunctions with large lattice-mismatch.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Chengzhao Chen ◽  
Cheng Li ◽  
Shihao Huang ◽  
Yuanyu Zheng ◽  
Hongkai Lai ◽  
...  

This paper describes the role of Ge as an enabler for light emitters on a Si platform. In spite of the large lattice mismatch of ~4.2% between Ge and Si, high-quality Ge layers can be epitaxially grown on Si by ultrahigh-vacuum chemical vapor deposition. Applications of the Ge layers to near-infrared light emitters with various structures are reviewed, including the tensile-strained Ge epilayer, the Ge epilayer with a delta-doping SiGe layer, and the Ge/SiGe multiple quantum wells on Si. The fundamentals of photoluminescence physics in the different Ge structures are discussed briefly.


Author(s):  
W. Qian ◽  
M. Skowronski ◽  
R. Kaspi ◽  
M. De Graef

GaSb thin film grown on GaAs is a promising substrate for fabrication of electronic and optical devices such as infrared photodetectors. However, these two materials exhibit a 7.8% lattice constant mismatch which raises concerns about the amount of extended defects introduced during strain relaxation. It was found that, unlike small lattice mismatched systems such as InxGa1-xAs/GaAs or GexSi1-x/Si(100), the GaSb/GaAs interface consists of a quasi-periodic array of 90° misfit dislocations, and the threading dislocation density is low despite its large lattice mismatch. This paper reports on the initial stages of GaSb growth on GaAs(001) substrates by molecular beam epitaxy (MBE). In particular, we discuss the possible formation mechanism of misfit dislocations at the GaSb/GaAs(001) interface and the origin of threading dislocations in the GaSb epilayer.GaSb thin films with nominal thicknesses of 5 to 100 nm were grown on GaAs(001) by MBE at a growth rate of about 0.8 monolayers per second.


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