Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: Colossal terahertz magnetoresistance at room temperature in epitaxial La0.7Sr0.3MnO3 nanocomposites and single-phase thin films

Journal Article · · Nano Letters
ORCiD logo [1];  [1];  [2];  [1]; ORCiD logo [3];  [4];  [5];  [5]
  1. Univ. of Warwick, Coventry (United Kingdom)
  2. Univ. of Oxford, Oxford (United Kingdom)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. Univ. at Buffalo, Buffalo, NY (United States)
  5. Univ. of Cambridge, Cambridge (United Kingdom)
+ Show Author Affiliations

Colossal magnetoresistance (CMR) is demonstrated at terahertz (THz) frequencies by using terahertz time-domain magnetospectroscopy to examine vertically aligned nanocomposites (VANs) and planar thin films of La0.7Sr0.3MnO3. At the Curie temperature (room temperature), the THz conductivity of the VAN was dramatically enhanced by over 2 orders of magnitude under the application of a magnetic field with a non-Drude THz conductivity that increased with frequency. The direct current (dc) CMR of the VAN is controlled by extrinsic magnetotransport mechanisms such as spin-polarized tunneling between nanograins. In contrast, we find that THz CMR is dominated by intrinsic, intragrain transport: the mean free path was smaller than the nanocolumn size, and the planar thin-film exhibited similar THz CMR to the VAN. Surprisingly, the observed colossal THz magnetoresistance suggests that the magnetoresistance can be large for alternating current motion on nanometer length scales, even when the magnetoresistance is negligible on the macroscopic length scales probed by dc transport. This suggests that colossal magnetoresistance at THz frequencies may find use in nanoelectronics and in THz optical components controlled by magnetic fields. As a result, the VAN can be scaled in thickness while retaining a high structural quality and offers a larger THz CMR at room temperature than the planar film.

Research Organization:
Los Alamos National Laboratory (LANL)
Sponsoring Organization:
LDRD; USDOE
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1364556
Report Number(s):
LA-UR-17-22535
Journal Information:
Nano Letters, Journal Name: Nano Letters Journal Issue: 4 Vol. 17; ISSN 1530-6984
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (35)

Self-Assembled Heteroepitaxial Oxide Nanocomposite Thin Film Structures: Designing Interface-Induced Functionality in Electronic Materials journal June 2010
Tunable Low-Field Magnetoresistance in (La0.7Sr0.3MnO3)0.5:(ZnO)0.5 Self-Assembled Vertically Aligned Nanocomposite Thin Films journal April 2011
A Review of the Terahertz Conductivity of Bulk and Nano-Materials journal May 2012
Transient Terahertz Conductivity of GaAs Nanowires journal July 2007
Direct evidence for a half-metallic ferromagnet journal April 1998
High-temperature electromagnons in the magnetically induced multiferroic cupric oxide driven by intersublattice exchange journal April 2014
Possible evidence for electromagnons in multiferroic manganites journal January 2006
Accessing the fundamentals of magnetotransport in metals with terahertz probes journal July 2015
Transport‐magnetism correlations in the ferromagnetic oxide La 0.7 Ca 0.3 MnO 3 journal August 1995
Low field magnetotransport properties of (La0.7Sr0.3MnO3)0.5:(ZnO)0.5 nanocomposite films journal May 2006
Terahertz transmission characteristics of high-mobility GaAs and InAs two-dimensional-electron-gas systems journal September 2006
Excellent low field magnetoresistance properties of the La0.7Sr0.3Mn1+dO3-manganese oxide composites journal August 2009
Microstructural and magnetic properties of (La 0.7 Sr 0.3 MnO 3 ) 0.7 :(Mn 3 O 4 ) 0.3 nanocomposite thin films journal March 2011
Interfacial and bulk polaron masses in Zn 1− x Mg x O/ZnO heterostructures examined by terahertz time-domain cyclotron spectroscopy journal May 2015
A.c. conduction in amorphous chalcogenide and pnictide semiconductors journal January 1987
Terahertz spectroscopy of quantum 2D electron systems journal August 2014
Extrinsic magnetotransport phenomena in ferromagnetic oxides journal January 2002
The essential interactions in oxides and spectral weight transfer in doped manganites journal November 1999
Ultrafast optical and far-infrared quasiparticle dynamics in correlated electron materials journal December 2002
Low field magnetotransport in manganites journal June 2008
Variation of electronic structure in La 1 − x Sr x MnO 3 f(0⩽x⩽0.3) as investigated by optical conductivity spectra journal February 1997
Optical conductivity of manganites: Crossover from Jahn-Teller small polaron to coherent transport in the ferromagnetic state journal December 1998
Colossal magneto-optical conductivity in doped manganites journal September 1999
Optical properties of small polarons from dynamical mean-field theory journal August 2006
Low-energy collective dynamics of charge stripes in the doped nickelate La 2 − x Sr x Ni O 4 + δ observed with optical conductivity measurements journal May 2008
Narrow heavy-hole cyclotron resonances split by the cubic Rashba spin-orbit interaction in strained germanium quantum wells journal July 2015
Direct Imaging of Nanoscale Phase Separation in La 0.55 Ca 0.45 MnO 3 : Relationship to Colossal Magnetoresistance journal August 2009
Optical Hall Effect in the Integer Quantum Hall Regime journal June 2010
Anomalous Variation of Optical Spectra with Spin Polarization in Double-Exchange Ferromagnet: La 1 − x Sr x MnO 3 journal July 1995
Carrier Density Collapse and Colossal Magnetoresistance in Doped Manganites journal January 1999
Ultrafast Conductivity Dynamics in Colossal Magnetoresistance Manganites journal June 2001
Theory of Insulator Metal Transition and Colossal Magnetoresistance in Doped Manganites journal April 2004
Carrier dynamics in semiconductors studied with time-resolved terahertz spectroscopy journal June 2011
Modifying the polarization state of terahertz radiation using anisotropic twin-domains in LaAlO_3 journal January 2014
Composite epitaxial thin films: A new platform for tuning, probing, and exploiting mesoscale oxides journal November 2015

Cited By (4)

Metal Oxide Nanocomposites: A Perspective from Strain, Defect, and Interface journal October 2018
Interfacial polarizations induced by incorporating traditional perovskites into reduced graphene oxide (RGO) for strong microwave response journal January 2019
Broadband microwave absorber constructed by reduced graphene oxide/La 0.7 Sr 0.3 MnO 3 composites journal January 2019
Giant positive magnetoresistance in half-metallic double-perovskite Sr 2 CrWO 6 thin films journal November 2017

Similar Records

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
Material Science