THE INFLUENCE OF NANOMETRIC SIZE ON VARIOUS PROPERTIES OF NANOCRYSTALLINE Zn0.9Ni0.1O DILUTED MAGNETIC SEMICONDUCTORS

With a view to understand the influence of nanometric size on various properties of nanocrystalline Zn0.9Ni0.1O diluted magnetic semiconductors, a systematic investigation has been undertaken. Samples were prepared for the first time by hydrazine assisted polyol method and are post annealed in air at different temperatures to vary the crystallite size. From the Rietveld refinement of XRD data, the isotropic crystallite size values are found to be in the range, 15–42 nm. Further, the phase analysis of Rietveld refined XRD data, FT-IR and optical absorbance spectral studies revealed that all the samples are having hexagonal wurzite structure without any detectable impurity phases. From AFM topography studies, it has been found that the surface condition of the grains and their distributions clearly depend on the nano size of the materials. From the PL measurements, the local defects of the materials were explored. From magnetization studies which were carried out by using VSM and MFM techniques, it has been found that all the samples are found to exhibit a clear ferromagnetic hysteresis behavior at room temperature without any magnetic clusters. Finally, electrical properties were also undertaken at room temperature to understand the variation of magnetic behavior as a function of nanometric size of these materials.

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Novel Room-temperature Ferromagnetic Semiconductors Pb1-x-yCaxCryTe

MRS Proceedings ◽

10.1557/proc-1183-ff06-04 ◽

2009 ◽

Vol 1183 ◽

Author(s):

Evgeny P. Skipetrov ◽

Elena A. Zvereva ◽

Nikolay A. Pichugin ◽

Alexey E. Primenko ◽

Evgeny I. Slyn'ko ◽

...

Keyword(s):

Magnetic Properties ◽

Curie Temperature ◽

Room Temperature ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Impurity Level ◽

Ferromagnetic Semiconductors ◽

Magnetization Curves ◽

Diluted Magnetic ◽

Ferromagnetic Ordering

Abstract The galvanomagnetic and magnetic properties of novel diluted magnetic semiconductors Pb1-x-yCaxCryTe (x=0.06-0.20, y=0.003-0.045) have been investigated. Temperature dependencies of the resistivity and the Hall coefficient have a metallic character indicating the pinning of Fermi level by the chromium impurity level on the background of the conduction band states. Magnetization curves display a clear hysteresis loop over the whole temperature range investigated. The Curie temperature, determined from the temperature dependencies of magnetization, achieves 345 K. Possible mechanisms of ferromagnetic ordering were discussed.

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STRUCTURAL, SURFACE MORPHOLOGICAL AND MAGNETIC STUDIES OF Zn1−xFexS (x=0.00–0.10) DILUTED MAGNETIC SEMICONDUCTORS GROWN BY CO-PRECIPITATION METHOD

Surface Review and Letters ◽

10.1142/s0218625x18500440 ◽

2018 ◽

Vol 25 (01) ◽

pp. 1850044

Author(s):

M. HASSAN ◽

M. GHAZANFAR ◽

N. AROOJ ◽

S. RIAZ ◽

S. SAJJAD HUSSAIN ◽

...

Keyword(s):

Crystallite Size ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Hysteresis Loops ◽

Secondary Phase ◽

Precipitation Method ◽

Ferromagnetic Behavior ◽

Magnetic Studies ◽

Diluted Magnetic ◽

Co Precipitation

We have fabricated Zn[Formula: see text]FexS ([Formula: see text], 0.02, 0.04, 0.06, 0.08 and 0.10) diluted magnetic semiconductors using co-precipitation method. X-ray diffraction patterns depict that Zn[Formula: see text]FexS appears as a dominant phase with cubic zinc blende structure and nanoscale crystallite size. In addition, a secondary phase of rhombohedral ZnS also appears; however, no additional phase arises that primarily belongs to Fe dopant. Using Debye–Scherrer relation, the crystallite size is found to be in the range of 20–27[Formula: see text]nm, which is in good agreement with the crystallite size calculated using the Williamson–Hall (WH) plot method. The appearance of secondary phase provoked to study the residual strain using Stokes–Wilson equation, which is nearly consistent to that observed using WH plot method. The surface morphology, revealed using scanning electron microscopy, depicts non-uniform surface structure with a variety of grains and void dimensions. Hysteresis loops measured for Zn[Formula: see text]FexS at room temperature (RT) illustrate a paramagnetic behavior at higher fields; however, small ferromagnetic behavior is evident due to the small openings of the measured hysteresis loops around the origin. The measured RT ferromagnetism reveals the potential spintronic device applications of the studied diluted magnetic semiconductors.

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Fabrication and Characterisation of Diluted Magnetic Semiconductors Thin Films Using Ion Beams

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.2869 ◽

2012 ◽

Vol 706-709 ◽

pp. 2869-2873

Author(s):

M. Ionescu ◽

P. Photongkam ◽

R. Siegele ◽

A. Deslantes ◽

S. Li ◽

...

Keyword(s):

Magnetic Properties ◽

Room Temperature ◽

Diluted Magnetic Semiconductors ◽

Depth Distribution ◽

Magnetic Semiconductors ◽

Ion Irradiation ◽

Research Effort ◽

Critical Parameters ◽

Ferromagnetic Behavior ◽

Diluted Magnetic

The intrinsic n-type (II-VI) semiconductor ZnO may become ferromagnetic at room temperature, by small additions of magnetic ions, resulting in what is called a Diluted Magnetic Semiconductors (DMS). The potential application of DMS in spintronic devices of is driving the research effort to dope magnetic elements into this semiconductors with a depth distribution as uniform as possible. The doping levels and the depth distribution of dopants are critical parameters for the magnetic properties of this material and the possible clustering of dopants can play a significant negative role in its macroscopic magnetic properties. Thin ZnO (0001) films of between 100nm and 500nm, grown on c-Al2O3 by MOCVD were implanted with Co, Eu and Co+Eu by ion irradiation at low energies. In order to improve the depth distribution of dopants, the ion implantation was carried out through a number of appropriately chosen range foils. The results show an increase in the level of dopant homogeneity throughout the entire thickness of the film, and a ferromagnetic behavior above room temperature for Zn0.96Co0.04O, Zn0.96Eu0.04O and Zn0.92Co0.04Eu0.04O.

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ESR Study of Novel Room-Temperature Ferromagnetic Semiconductors Pb1-X-YSnxCryTe

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.168-169.404 ◽

2010 ◽

Vol 168-169 ◽

pp. 404-407

Author(s):

E.A. Zvereva ◽

O.A. Savelieva ◽

S. Ibragimov ◽

E. Samokhvalov ◽

E.I. Slynko ◽

...

Keyword(s):

Room Temperature ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Magnetic Ordering ◽

Esr Spectra ◽

Chromium Concentration ◽

Ferromagnetic Phase ◽

Wide Range ◽

Diluted Magnetic ◽

Ordering Transition

We report on the magnetic properties of novel diluted magnetic semiconductors Pb1 x ySnxCryTe revealing ferromagnetism at temperatures higher than room temperature. Depending on chromium concentration the Curie temperature varies in a wide range (150360 K) and effective magnetic moment achieves 1 B upon an increase of chromium doping level. Electron spin resonance (ESR) spectra in the paramagnetic phase were satisfactory approximated by a single Dysonian line. Effective g-factor tends to the saturation value g=2.080.01, while the linewidth passes through a minimum in the vicinity of magnetic ordering transition and then broadens with an increase of the temperature. In ferromagnetic phase the pronounced distortion and splitting of the ESR spectra into two lines occurs due to additional ferromagnetic contribution to absorption.

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Room temperature ferromagnetic Cr–Ni codoped ZnO diluted magnetic semiconductors synthesized by hydrothermal method under high pulsed magnetic field

Ceramics International ◽

10.1016/j.ceramint.2014.08.091 ◽

2015 ◽

Vol 41 (1) ◽

pp. 451-457 ◽

Cited By ~ 21

Author(s):

Min Zhong ◽

Shiwei Wang ◽

Ying Li ◽

Yemin Hu ◽

Mingyuan Zhu ◽

...

Keyword(s):

Magnetic Field ◽

Hydrothermal Method ◽

Room Temperature ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Pulsed Magnetic Field ◽

Diluted Magnetic

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Nanoscale Engineering of Ge-based Diluted Magnetic Semiconductors for Room-Temperature Spintronics Application

Molecular Beam Epitaxy ◽

10.1016/b978-0-12-812136-8.00020-7 ◽

2018 ◽

pp. 403-419

Author(s):

Tianxiao Nie ◽

Jianshi Tang ◽

Xufeng Kou ◽

Faxian Xiu ◽

Kang L. Wang

Keyword(s):

Room Temperature ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Diluted Magnetic

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Combinatorial Investigation of Spintronic Materials

MRS Bulletin ◽

10.1557/mrs2003.215 ◽

2003 ◽

Vol 28 (10) ◽

pp. 734-739 ◽

Cited By ~ 21

Author(s):

Y. Matsumoto ◽

H. Koinuma ◽

T. Hasegawa ◽

I. Takeuchi ◽

F. Tsui ◽

...

Keyword(s):

Transition Metal ◽

Metal Oxides ◽

Transition Metal Oxides ◽

Room Temperature ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Magnetic Transition ◽

Heusler Alloys ◽

Oxide Systems ◽

Diluted Magnetic

AbstractHigh-throughput synthesis and characterization techniques have been effective in discovering new materials and performing rapid mapping of phase diagrams. The application of the combinatorial strategy to explore doped transition-metal oxides has led to the discovery of a transparent room-temperature ferromagnetic oxide in Co-doped anatase TiO2. The discovery has triggered a wave of studies into other metal oxide systems in pursuit of diluted magnetic semiconductors. In this article, we describe recent combinatorial studies of magnetic transition-metal oxides, germanium-based magnetic semiconductors, and Heusler alloys.

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