Submillimeter wave ESR measurement of LaMnO3

Mitsudo, S.; Hirano, Ken‐ichi; Nojiri, Hiroyuki; Motokawa, M.; Hirota, K.; Nishizawa, Akinori; Kaneko, Nobu‐Hisa; Endoh, Y.

doi:10.1016/s0304-8853(97)00525-8

Cited by 31 publications

(27 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Its value determined by neutron diffraction is 620 GHz at 4 K, which is much higher than our measurement frequency. Similar results were obtained by Mitsudo et al [26]. Here also, it seems that we do not get any signature of Mn 3 + ions, but there is still an absorption line at g = 2.0 reflecting probably the presence of Mn" with an enhanced susceptibility.…”

Section: High-frequency Spectrum Ofsupporting

confidence: 92%

Origin of the electron spin resonance signal in the manganites: from polarons to phase separation

et al. 2000

View full text Add to dashboard Cite

In the manganites L,_,M,MnO 3 (L = La, Nd, Pr, ...; M = Sr, Ba, Ca, ...), the doping concentration introduces a mixed valence (Mn", Mn") which governs the magnetic and electric properties of the compound. Mn 3 + (S = 2) is scarcely observed in electron spin resonance (ESR). In contrast, Mn^+ (S = 3/2), is a good ESR probe. However, X-band measurements show an enhanced Mn°+ susceptibility, which is the signature of some kind of coupling of the Mn°+ ions with the Mn'+ ions, but its exact nature is still controversial. We present multifrequency ESR experiments (9-385 GHz) obtained on different systems (La, Mn0 3 , La,MnO3, La 1 _ rCaxMnO 3 , and Nd,_,Ca MnO 3 ) in the low-concentration range (0 <_ x < 0.33). In the paramagnetic regime, the Mn 3 + spectrum cannot be observed because of fast relaxation. The signal arises from polarons, whose size, temperature and magnetic field dependences vary with M and x. The single line observed in the metallic compound evolves towards a double-peak structure visible at high frequency in Lao 97 MnO3 . Its evolution with temperature below the magnetic transition reveals the presence of manganese ions in a different magnetic environment, i.e., phase separation. The magnetic order of the separated phase is not ferromagnetic. It is a more complex order, which depends substantially on the nature of the cation M.

show abstract

Section: High-frequency Spectrum Ofsupporting

confidence: 92%

Origin of the electron spin resonance signal in the manganites: from polarons to phase separation

et al. 2000

View full text Add to dashboard Cite

show abstract

“…The obtained data are in qualitative agreement with the results of previous studies [1][2][3][5][6][7]; some discrepancies may arise because of a small difference in cation and oxygen stoichiometries. The present results confirm existence of canted magnetic structure A a F b type in LaMnO 3 .…”

Section: Article In Presssupporting

confidence: 90%

“…Analyzing these experiments together with MðHÞ curves for main crystallographic directions ( Fig. 2) and taking into account previous data on the structure and magnetic properties of LaMnO 3 [1][2][3][4][5][6][7], we conclude that the cubic axes [0 0 1], [1 1 0] and [À1 1 0] should be considered as b-, a-and c-axes in the orthorhombic P nma description.…”

mentioning

confidence: 74%

See 1 more Smart Citation

Anisotropy of magnetic properties in LaMnO3 single crystals

Korolyov

Архипов

Гавико

et al. 2004

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

“…This change in orientation and symmetry lowering results in a change of the magnetic easy axis direction relative to the substrate. In bulk A-AFM eP bnm LaMnO 3 , the magnetic easy axis is along [110], 7,10,63 and the measured magnetocrystalline anisotropy energy is 0.66 meV/f.u., 63 and further, as a result of the lower symmetry, the easy axis is slightly tilted from a (by 18 • ) forming an angle of 27 • with the substrate. A discontinuous change in the direction of the FM easy axis, from [110] to [074], is thus expected at 0% strain.…”

mentioning

confidence: 99%

Strong coupling of Jahn-Teller distortion to oxygen-octahedron rotation and functional properties in epitaxially strained orthorhombic LaMnO3

et al. 2013

View full text Add to dashboard Cite

First-principles calculations reveal a large cooperative coupling of Jahn-Teller (JT) distortion to oxygenoctahedron rotations in perovskite LaMnO 3 . The combination of the two distortions is responsible for stabilizing the strongly orthorhombic A-AFM insulating (I ) eP bnm ground state relative to a metallic ferromagnetic (FM-M) phase. However, epitaxial strain due to coherent matching to a crystalline substrate can change the relative stability of the two states. In particular, coherent matching to a square-lattice substrate favors the less orthorhombic FM-M phase, with the A-AFM phase stabilized at higher values of tensile epitaxial strain due to its larger volume per formula unit, resulting in a coupled magnetic and metal-insulator transition at a critical strain close to 1%. At the phase boundary, a very large magnetoresistance is expected. Tensile epitaxial strain enhances the JT distortion and opens the band gap in the A-AFM-I c-eP bnm phase, offering the opportunity for band-gap engineering. Compressive epitaxial strain induces a transition within the FM-M phase from the c-eP bnm orientation to the ab-eP bnm orientation with a change in the direction of the magnetic easy axis relative to the substrate, yielding strain-controlled magnetization at the phase boundary. Similar behavior is expected in other JT active P bnm perovskites. (La,M)MnO 3 (M = Ca, Pr, Sr, Ba) has been of great interest due to the couplings among structure, magnetic and orbital orderings, and the resulting functional properties, such as colossal magneto-resistance (CMR). 1-4 As a result, there have been many experimental 5-8 and theoretical 9-25 studies of the end-member compound LaMnO 3 (LaMnO 3 ). The observed sequence of phases with decreasing temperature is as follows: 8,26 At very high temperature (above 1010 K), LaMnO 3 has a rhombohedral R3c structure, produced by rotation of the oxygen octahedron network of the ideal perovskite structure. From 1010 K down to 750 K, it has an orthorhombic P bnm structure produced by a different pattern of octahedral rotations. At 750 K, an orbital-order transition occurs by a cooperative Jahn-Teller transition; 27 however, this distortion does not break the symmetry of the P bnm structure. Finally, a magnetic transition to an A-type antiferromagnetic (A-AFM) ordering (ferromagnetic alignment in the xy planes, with spin direction alternating from plane to plane) occurs at 135 K.It proves to be challenging to reproduce the observed A-AFM ground state of LaMnO 3 , with its half filled e g level, from first principles. If the structural parameters are fixed to the experimental values, the correct magnetic ordering is obtained with a range of density-functional-theory (DFT) methods. However, full optimization of the structure within DFT generally gives a competing FM-M phase as the ground state, 11,17 and the correct ground state is obtained only in calculations with both a generalized gradient form of the density functional and inclusion of a Hubbard U . 16 More generally, various couplings in com...

show abstract

Submillimeter wave ESR measurement of LaMnO3

Cited by 31 publications

References 6 publications

Origin of the electron spin resonance signal in the manganites: from polarons to phase separation

Origin of the electron spin resonance signal in the manganites: from polarons to phase separation

Anisotropy of magnetic properties in LaMnO3 single crystals

Strong coupling of Jahn-Teller distortion to oxygen-octahedron rotation and functional properties in epitaxially strained orthorhombic LaMnO3

Contact Info

Product

Resources

About