Interplay Between Electronic Transport and Magnetic Order in Ferromagnetic Manganite Thin Films

1997 ◽  
Vol 474 ◽  
Author(s):  
M. R. Hundley ◽  
J. J. Neumeier ◽  
R. H. Heffher ◽  
Q. X. Jia ◽  
X. D. Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Transport ◽  
Transition Metal Oxides ◽  
Colossal Magnetoresistance ◽  
Magnetic Order ◽  
Magnetic Ordering ◽  
Temperature Dependent ◽  
Sharp Maximum ◽  
Magnetic Ordering Temperature ◽  
Dependent Transport

ABSTRACTThe transition metal oxides La1-xAxMnO3 (A = Ba, Ca, or Sr) order ferromagnetically with Curie temperatures ranging from as low as 50 K to well above room temperature. Magnetic order in these compounds results in a concomitant metal-insulator transition. The feature displayed by the manganites that is most important technologically is the extremely large negative magnetoresistance that achieves its largest values near the magnetic ordering temperature. Qualitatively, this colossal magnetoresistance (CMR) phenomenon involves the suppression of the relatively sharp maximum in the resistivity that is centered at Tc. When considered collectively, the anomalous temperature-dependent transport properties, the CMR effect, and the magnetically ordered ground state indicate that a novel interplay between magnetism and electronic transport occurs in the manganites. General features of the magnetic-field and temperature-dependent electrical resistivity and magnetization as displayed by PLD-grown thin films are examined. Particular emphasis is placed on what these measurements tell us about the conduction process both above and below the magnetic ordering temperature.

scholarly journals Doping dependent electronic and magnetic ordering in mixed-valent La1−xSrxMnO3 thin films

2021 ◽  
Author(s):  
James A. Payne ◽  
Charles T. Bryant ◽  
Rodolfo Marquez Tavera ◽  
Dakota T. Brown ◽  
Thomas M. Pekarek ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Transport ◽  
Ground State ◽  
Parent Compound ◽  
Magnetic Ordering ◽  
Bulk Crystals ◽  
Temperature Dependent ◽  
Jahn Teller ◽  
Antiferromagnetic Ground State ◽  
Ferromagnetic Ordering

Abstract We have investigated the collective electronic and magnetic orderings of a series of La1−xSrxMnO3 thin films grown epitaxially strained to (001) oriented strontium titanate substrates as a function of doping, x, for 0 ≤ x ≤ 0.4. We find that the ground states of these crystalline thin films are, in general, consistent with that observed in bulk crystals and thin film samples synthesized under a multitude of techniques. Our systematic study, however, reveal subtle features in the temperature dependent electronic transport and magnetization measurements, which presumably arise due to Jahn-Teller type distortions in the lattice for particular doping levels. For the parent compound LaMnO3 (x = 0), we report evidence of a strain-induced ferromagnetic ordering in contrast to the antiferromagnetic ground state found in bulk crystals.

Sub-200 Oe Giant Magnetoresistance in Manganite Tunnel Junctions

1997 ◽  
Vol 494 ◽  
Author(s):  
Gang Xiao ◽  
A. Gupta ◽  
X. W. Li ◽  
G. Q. Gong ◽  
J. Z. Sun
Keyword(s):  
Electronic Structure ◽  
Colossal Magnetoresistance ◽  
Giant Magnetoresistance ◽  
Domain Walls ◽  
Tunnel Junctions ◽  
Research Effort ◽  
Boundary Effect ◽  
Magnetic Domain ◽  
Magnetic Ordering ◽  
Dependent Transport

ABSTRACTMetallic manganite oxides, La1-xDxMnO3 (D=Sr, Ca, etc.), display “colossal” magnetoresistance (CMR) near their magnetic phase transition temperatures (Tc) when subject to a Tesla-scale magnetic field. This phenomenal effect is the result of the strong interplay inherent in this class of materials among electronic structure, magnetic ordering, and lattice dynamics. Though fundamentally interesting, the CMR effect achieved only at large fields poses severe technological challenges to potential applications in magnetoelectronic devices, where low field sensitivity is crucial. Among the objectives of our research effort involving manganite materials is to reduce the field scale of MR by designing and fabricating tunnel junctions and other structures rich in magnetic domain walls. The junction electrodes were made of doped manganite epitaxial films, and the insulating barrier of SrTiO3. The interfacial expitaxy has been imaged by using high-resolution transmission electron microscopy (TEM). We have used self-aligned lithographic process to pattern the junctions to micron scale in size. Large MR values close to 250% at low fields of a few tens of Oe have been observed. The mechanism of the spin-dependent transport is due to the spin-polarized tunneling between the half-metallic electrodes, in which the spins of the conduction electrons are nearly fully polarized. We will present results of field and temperature dependence of MR in these structures and discuss the electronic structure of the manganite inferred from tunneling measurement. Results of large MR at low fields due to the grain-boundary effect will also be presented.

scholarly journals Interplay between electronic transport and magnetic order in ferromagnetic magnetic manganite thin films

1997 ◽  
Author(s):  
M.F. Hundley ◽  
J.J. Neumeier ◽  
R.H. Heffner ◽  
Q.X. Jia ◽  
X.D. Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Transport ◽  
Magnetic Order

Field and temperature-dependent electronic transport parameters of amorphous and polycrystalline GaSe thin films

2003 ◽  
Vol 337 (1-4) ◽  
pp. 404-412 ◽  
Author(s):  
M Thamilselvan ◽  
K Premnazeer ◽  
D Mangalaraj ◽  
Sa.K Narayandass
Keyword(s):  
Thin Films ◽  
Electronic Transport ◽  
Transport Parameters ◽  
Temperature Dependent

Magnetic Cluster Expansion Study of Chromium Precipitates in Fe-Cr Alloys

2011 ◽  
Vol 172-174 ◽  
pp. 1002-1007 ◽  
Author(s):  
Mikhail Yu. Lavrentiev ◽  
Duc Nguyen Manh ◽  
Sergei L. Dudarev
Keyword(s):  
Cluster Expansion ◽  
Magnetic Order ◽  
Magnetic Ordering ◽  
Expansion Method ◽  
Temperature Dependent ◽  
Magnetic Cluster ◽  
Cluster Expansion Method ◽  
Atom Pairs ◽  
Characteristic Variation ◽  
Magnetic Specific Heat

Magnetic Cluster Expansion method is applied to the investigation of magnetic properties of Fe-Cr alloys treated as a function of Cr content, the spatial distribution of Cr atoms, and temperature. Random Fe-Cr alloys and Cr clusters formed in concentrated alloys are analyzed. We find significant differences between the types of magnetic order characterizing those systems, which are reflected in the characteristic variation of the temperature-dependent magnetic specific heat. Simulations show that in random Fe-Cr alloys and in alloys containing Cr clusters, the interplay between antiferromagnetic interactions characterizing Fe-Cr and Cr-Cr atom pairs gives rise to unusual patterns of finite temperature magnetic ordering.

Size and chemical order dependence of magnetic-ordering temperature and spin structure in Fe@Ni and Ni@Fe core–shell nanoparticles

2020 ◽  
Vol 22 (11) ◽  
pp. 6275-6281
Author(s):  
Junais Habeeb Mokkath
Keyword(s):  
Spin Structure ◽  
Magnetic Ordering ◽  
Core Shell ◽  
Spin Hamiltonian ◽  
Temperature Dependent ◽  
Shell Nanoparticles ◽  
Chemical Order ◽  
Effect Of Particle Size ◽  
Magnetic Ordering Temperature ◽  
Core Shell Nanoparticles

The effect of particle size and chemical order on the temperature-dependent magnetic properties of Fe@Ni and Ni@Fe core–shell nanoparticles is studied in the framework of a classical spin Hamiltonian and Monte Carlo simulations.

Elevated temperature dependent transport properties of phosphorus and arsenic doped zinc oxide thin films

2013 ◽  
Vol 114 (22) ◽  
pp. 223709 ◽  
Author(s):  
B. Cai ◽  
M. L. Nakarmi ◽  
T. N. Oder ◽  
M. McMaster ◽  
N. Velpukonda ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Elevated Temperature ◽  
Transport Properties ◽  
Oxide Thin Films ◽  
Temperature Dependent ◽  
Dependent Transport

Magnetic Ordering via Itinerant Ferromagnetism in a Metal-Organic Framework

2020 ◽  
Author(s):  
Jesse Park ◽  
Brianna Collins ◽  
Lucy Darago ◽  
Tomce Runcevski ◽  
Michael Aubrey ◽  
...  
Keyword(s):  
Charge Transport ◽  
Magnetic Order ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Magnetic Ordering ◽  
Double Exchange ◽  
Itinerant Ferromagnetism ◽  
Organic Solids ◽  
Metal Organic ◽  
Organic Framework

<b>Materials that combine magnetic order with other desirable physical attributes offer to revolutionize our energy landscape. Indeed, such materials could find transformative applications in spintronics, quantum sensing, low-density magnets, and gas separations. As a result, efforts to design multifunctional magnetic materials have recently moved beyond traditional solid-state materials to metal–organic solids. Among these, metal–organic frameworks in particular bear structures that offer intrinsic porosity, vast chemical and structural programmability, and tunability of electronic properties. Nevertheless, magnetic order within metal–organic frameworks has generally been limited to low temperatures, owing largely to challenges in creating strong magnetic exchange in extended metal–organic solids. Here, we employ the phenomenon of itinerant ferromagnetism to realize magnetic ordering at <i>T</i><sub>C</sub> = 225 K in a mixed-valence chromium(II/III) triazolate compound, representing the highest ferromagnetic ordering temperature yet observed in a metal–organic framework. The itinerant ferromagnetism is shown to proceed via a double-exchange mechanism, the first such observation in any metal–organic material. Critically, this mechanism results in variable-temperature conductivity with barrierless charge transport below <i>T</i><sub>C</sub> and a large negative magnetoresistance of 23% at 5 K. These observations suggest applications for double-exchange-based coordination solids in the emergent fields of magnetoelectrics and spintronics. Taken together, the insights gleaned from these results are expected to provide a blueprint for the design and synthesis of porous materials with synergistic high-temperature magnetic and charge transport properties. </b>

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