Seebeck and Spin Seebeck effect in Gd-doped GaN thin films for Thermoelectric Devices and Applications

ABSTRACTGaN-based dilute magnetic semiconductors (DMS) have recently been investigated for use in spintronic devices. In particular, Gd-doped GaN has shown very promising room temperature ferromagnetic behavior and potential for use in spintronics applications. III-Nitride materials have recently had their thermoelectric properties investigated; however this work has not been extended to Nitride-based DMS. Understanding the spin-calorimetric characteristics of GaN-based DMS is important to the successful development of low-power spintronic devices. In this paper the Seebeck and spin-Seebeck effect in MOCVD grown Gd-doped GaN (Gd: GaN) are investigated.

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THE GROWTH AND CHARACTERIZATION OF ROOM TEMPERATURE FERROMAGNETIC WIDEBAND-GAP MATERIALS FOR SPINTRONIC APPLICATIONS

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156406003825 ◽

2006 ◽

Vol 16 (02) ◽

pp. 515-543

Author(s):

MATTHEW H. KANE ◽

MARTIN STRASSBURG ◽

WILLIAM E. FENWICK ◽

ALI ASGHAR ◽

IAN T. FERGUSON

Keyword(s):

Room Temperature ◽

Magnetic Semiconductors ◽

Room Temperature Ferromagnetism ◽

Dilute Magnetic Semiconductors ◽

Chemical Vapor ◽

Wide Bandgap ◽

Organic Chemical ◽

Ferromagnetic Behavior ◽

Spintronic Devices

Wide-bandgap dilute magnetic semiconductors (DMS), such as transition-metal doped ZnO and GaN , have gained attention for use in spintronic devices because of predictions and experimental reports of room temperature ferromagnetism which may enable their use in spintronic devices. However, there has been some debate over the source of ferromagnetism in these materials. This paper focuses on the high quality growth of wide bandgap DMS, and the characterization of Zn 1-x Mn x O produced by melt-growth techniques and Ga 1-x Mn x N grown by metal organic chemical vapor deposition (MOCVD). High resolution X-ray diffraction results revealed no second phases in either the ZnO crystals or the GaN films. Undoped as-grown, bulk crystals of Zn 1-x Mn x O and Zn 1-x Co x O crystals are shown to be paramagnetic at all temperatures. In contrast, the Ga 1-x Mn x N films showed ferromagnetic behavior at room temperature under optimum growth conditions. Experimental identification of the Mn ion charge state and the presence of bands in the bandgap of GaN are investigated by optical spectroscopy and electron spin paramagnetic resonance (EPR). It is shown that the broadening of states in the Mn 3d shell scaled with Mn concentration, and that optical transitions due to this band correlated with the strong ferromagnetism in these samples. However, this band disappeared with an increase in free electron concentration provided by either annealing or doping. Raman studies of Ga 1-x Mn x N revealed two predominant Mn -related modes featured with increasing concentration, a broad disorder related structure at 300cm-1 and a sharper peak at 669cm-1 This works show that the development of practical ferromagnetic wide bandgap DMS materials for spintronic applications will require both the lattice site introduction of Mn as well as careful control of the background defect concentration to optimize these materials.

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Electric detection of the spin-Seebeck effect in Ni and Fe thin films at room temperature

Journal of Physics Conference Series ◽

10.1088/1742-6596/200/6/062020 ◽

2010 ◽

Vol 200 (6) ◽

pp. 062020 ◽

Cited By ~ 4

Author(s):

T Ota ◽

K Uchida ◽

Y Kitamura ◽

T Yoshino ◽

H Nakayama ◽

...

Keyword(s):

Thin Films ◽

Room Temperature ◽

Seebeck Effect ◽

Spin Seebeck Effect ◽

Electric Detection

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Magneto-transport Properties of Gd-doped In2O3 Thin Films

MRS Proceedings ◽

10.1557/proc-1032-i06-04 ◽

2007 ◽

Vol 1032 ◽

Cited By ~ 2

Author(s):

Ram Gupta ◽

D. Brown ◽

K. Ghosh ◽

S. R. Mishra ◽

P. K. Kahol

Keyword(s):

Thin Films ◽

Rare Earth ◽

Room Temperature ◽

Magnetic Semiconductors ◽

Dilute Magnetic Semiconductors ◽

Growth Conditions ◽

Electronic Charge ◽

X Ray Diffraction ◽

X Ray ◽

Electro Magnetic

AbstractDilute Magnetic Semiconductors (DMS) are a rare group of promising materials that utilize both the electronic charge - a characteristic of semiconductor materials - and the electronic spin - a characteristic of magnetic materials. Oxide based DMS show promise of ferromagnetism (FM) at room temperature. It has been found that doping metal oxides such as ZnO, TiO2, and In2O3 with magnetic ions such as Fe, Co, Mn, and Cr produces DMS, which exhibit FM above room temperature. In2O3, a transparent opto-electronic material, is an interesting prospect for spintronics due to a unique combination of magnetic, electrical, and optical properties. High quality thin films of rare earth magnetic gadolinium (Gd) doped oxide-based DMS materials have been grown by pulsed laser deposition (PLD) technique on various substrates such as single crystal of sapphire (001) and quartz under suitable growth conditions of substrate temperature and oxygen pressure in the PLD chamber. The effect of rare earth magnetic doping on the structural and electro - magnetic properties of these films has been studied using Raman Spectroscopy, X-Ray Diffraction, Scanning Electron Microscopy, and Magneto - Transport. An X- ray diffraction study reveals that these films are single phase and highly oriented. Characteristic Raman peaks typical of indium oxide are observed at 496 and 627 cm−1. We have observed high magnetoresistance (∼18 %) at a relatively small field of 1.3 Tesla for the films with 10 % gadolinium. A detailed study of temperature and magnetic field dependent resistivity, magnetoresistance, and Hall Effect will be presented.

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Room temperature and low-field resonant enhancement of spin Seebeck effect in partially compensated magnets

Nature Communications ◽

10.1038/s41467-019-13121-5 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 7

Author(s):

R. Ramos ◽

T. Hioki ◽

Y. Hashimoto ◽

T. Kikkawa ◽

P. Frey ◽

...

Keyword(s):

Magnetic Fields ◽

Room Temperature ◽

Seebeck Effect ◽

Chemical Doping ◽

Resonant Enhancement ◽

Spintronic Devices ◽

Spin Seebeck Effect ◽

Potential Applications ◽

Order Of Magnitude ◽

Magnetic Ion

AbstractResonant enhancement of spin Seebeck effect (SSE) due to phonons was recently discovered in Y$${}_{3}$$3Fe$${}_{5}$$5O$${}_{12}$$12 (YIG). This effect is explained by hybridization between the magnon and phonon dispersions. However, this effect was observed at low temperatures and high magnetic fields, limiting the scope for applications. Here we report observation of phonon-resonant enhancement of SSE at room temperature and low magnetic field. We observe in Lu$${}_{2}$$2BiFe$${}_{4}$$4GaO$${}_{12}$$12 an enhancement 700% greater than that in a YIG film and at very low magnetic fields around 10$${}^{-1}$$−1 T, almost one order of magnitude lower than that of YIG. The result can be explained by the change in the magnon dispersion induced by magnetic compensation due to the presence of non-magnetic ion substitutions. Our study provides a way to tune the magnon response in a crystal by chemical doping, with potential applications for spintronic devices.

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Atom-Probe Tomographic Studies of Thin Films and Multilayers

MRS Bulletin ◽

10.1557/mrs2009.247 ◽

2009 ◽

Vol 34 (10) ◽

pp. 732-737 ◽

Cited By ~ 23

Author(s):

David J. Larson ◽

Alfred Cerezo ◽

Jean Juraszek ◽

Kazuhiro Hono ◽

Guido Schmitz

Keyword(s):

Thin Films ◽

Atom Probe Tomography ◽

Room Temperature ◽

Film Growth ◽

Thermal Evolution ◽

Magnetic Semiconductors ◽

Room Temperature Ferromagnetism ◽

Dilute Magnetic Semiconductors ◽

Atom Probe ◽

Theory And Modeling

AbstractThis article reviews investigations of the growth and reactions within thin metal and oxide films using atom-probe tomography. Included in this review are (1) studies of interfacial and growth reactions in magnetoresistive metallic, metal/oxide, and magnetic magnetostrictive multilayers; (2) comparison of selected portions of these results to simulated film growth using molecular dynamics; and (3) study of the origin of room-temperature ferromagnetism in dilute magnetic semiconductors. Information of this type is useful in order to understand the formation and thermal evolution of thin films (and to compare to theory and modeling) and, ultimately, to permit further optimization of devices based on thin films.

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Review on Available Theoretical Models for Room Temperature Ferromagnetism in Dilute Magnetic Semiconductors

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.11(3).03039 ◽

2019 ◽

Vol 11 (3) ◽

pp. 03039-1-03039-3 ◽

Cited By ~ 1

Author(s):

Rana Mukherji ◽

◽

Vishal Mathur ◽

Keyword(s):

Room Temperature ◽

Magnetic Semiconductors ◽

Room Temperature Ferromagnetism ◽

Dilute Magnetic Semiconductors ◽

Theoretical Models

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Room temperature ferromagnetism in III–V and II–IV–V2 dilute magnetic semiconductors

Physica B Condensed Matter ◽

10.1016/j.physb.2005.11.124 ◽

2006 ◽

Vol 374-375 ◽

pp. 430-432 ◽

Cited By ~ 9

Author(s):

V.G. Storchak ◽

D.G. Eshchenko ◽

H. Luetkens ◽

E. Morenzoni ◽

R.L. Lichti ◽

...

Keyword(s):

Room Temperature ◽

Magnetic Semiconductors ◽

Room Temperature Ferromagnetism ◽

Dilute Magnetic Semiconductors

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Morphology-dependent spin Seebeck effect in yttrium iron garnet thin films prepared by metal-organic decomposition

Ceramics International ◽

10.1016/j.ceramint.2021.02.249 ◽

2021 ◽

Author(s):

Trinh Nguyen Thi ◽

Phuoc Cao Van ◽

Duc Duong Viet ◽

Viet Dong Quoc ◽

Hayeong Ahn ◽

...

Keyword(s):

Thin Films ◽

Yttrium Iron Garnet ◽

Seebeck Effect ◽

Yttrium Iron ◽

Spin Seebeck Effect ◽

Metal Organic ◽

Iron Garnet ◽

Organic Decomposition

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Assessment of Magnetic Properties between Fe and Ni Doped ZnO Nanoparticles Synthesized by Microwave Assisted Synthesis Method

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.317.119 ◽

2021 ◽

Vol 317 ◽

pp. 119-124

Author(s):

Sabiu Said Abdullahi ◽

Garba Shehu Musa Galadanci ◽

Norlaily Mohd Saiden ◽

Josephine Ying Chyi Liew

Keyword(s):

Magnetic Properties ◽

Zno Nanoparticles ◽

Room Temperature ◽

Synthesis Method ◽

Dilute Magnetic Semiconductors ◽

High Coercivity ◽

Microwave Assisted Synthesis ◽

Ferromagnetic Behavior ◽

Microwave Assisted ◽

Doped Zno

The emergence of Dilute Magnetic Semiconductors (DMS) with a potentials for spintronic application have attracted much researches attention, special consideration has been given to ZnO semiconductor material due to its wide band gap of 3.37 eV, large exciting binding energy of 60 meV, moreover, its ferromagnetic behavior at room temperature when doped with transition metals. MxZn1-xO (M = Fe or Ni) nanoparticles were synthesized by microwave assisted synthesis method calcined at 600°C. The structural, morphological and magnetic properties of these nanoparticles were studied using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Vibrating Sample Magnetometer (VSM) respectively. Single phase Wurtzite hexagonal crystal structure was observed for the undoped and Fe doped ZnO nanoparticles with no any impurity, whereas Ni doped ZnO nanoparticles shows the formation of NiO impurities. The magnetic measurement reveals a diamagnetic behavior for the undoped ZnO meanwhile a clear room temperature ferromagnetism was observed for both Fe and Ni doped ZnO. Fe doped ZnO present a high saturation magnetization compared to Ni doped ZnO. However, Ni doped ZnO present high coercivity. The research was confirmed that Fe doped ZnO material will be good material combination for spintronic applications.

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