Magnetic properties of heavy-rare-earth orthomanganites

Wood, Van E.; Austin, A.E.; Collings, E. W.; Brog, K. C.

doi:10.1016/s0022-3697(73)80088-5

Cited by 80 publications

(45 citation statements)

References 20 publications

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“…In the dc magnetization data reported by Muñoz et al, 12 only a subtle kink is visible at about 40 K. In contrast, earlier measurements by Wood et al 6 and more recent data by Lorenz et al 10 display a -like peak at T N . The observation of hysteresis in ZFC-FC data is interesting on its own.…”

Section: Resultsmentioning

confidence: 81%

“…5 YMnO 3 is on the verge of stability between hexagonal and orthorhombic phases. Although under normal synthesis conditions, the hexagonal phase is the stable one, the metastable orthorhombic o-YMnO 3 phase can be obtained using either high pressures (bulk materials) 6 or appropriate epitaxial strain engineering (thin films). [7][8][9] It has been reported that polycrystalline o-YMnO 3 displays a pronounced dielectric constant (⑀) anomaly at T⑀ < T N , 10 which has been taken as a signature of magnetoelectric coupling.…”

Section: Introductionmentioning

confidence: 99%

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Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO₃ thin films

et al. 2007

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The structure, magnetic response, and dielectric response of the grown epitaxial thin films of the orthorhombic phase of YMnO 3 oxide on Nb:SrTiO 3 (001) substrates have been measured. We have found that a substrate-induced strain produces an in-plane compression of the YMnO 3 unit cell. The magnetization versus temperature curves display a significant zero-field cooling (ZFC)-field cooling hysteresis below the Néel temperature (T N ≈ 45 K). The dielectric constant increases gradually (up to 26%) below the T N and mimics the ZFC magnetization curve. We argue that these effects could be a manifestation of magnetoelectric coupling in YMnO 3 thin films and that the magnetic structure of YMnO 3 can be controlled by substrate selection and/or growth conditions.

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Section: Resultsmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO₃ thin films

et al. 2007

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“…To form Ortho-YMnO 3 , the lowest pressure reported to date was ~3.4 GPa at ~920 K [41]. When temperature is higher than 1270 K [6,7,41,42], the required phase transition pressure is reduced significantly. Based on our fixed temperature and fixed pressure experiments, we deduce a mixed phase region of Hex-YMnO 3 and Ortho-YMnO 3 existing for temperatures below 920 K. Apart from the pressure and temperature, another important factor is the duration time for the Ortho-REMnO 3 synthesis, which is not addressed here.…”

Section: Resultsmentioning

confidence: 99%

High-pressure structural stability of multiferroic hexagonalRMnO3(R=Y, Ho, Lu)

et al. 2011

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Structural changes in REMnO 3 (RE= Y, Ho, Lu) under high pressure were examined by synchrotron x-ray diffraction methods at room temperature. Compression occurs more readily in the ab plane than along the c-axis. With increased pressure, a pressure-induced hexagonal to orthorhombic phase transition was observed starting at ~ 22 GPa for Lu(Y)MnO 3 . When the pressure is increased to 35 GPa, a small volume fraction of Lu(Y)MnO 3 is converted to the orthorhombic phase and the orthorhombic phase is maintained on pressure release. High pressure IR absorption spectroscopy and Mn K-edge near edge x-ray absorption spectroscopy confirm that the hexagonal P6 3 cm structure is stable below ~20 GPa and the environment around Mn ion is not changed. Shifts in the unoccupied p-band density of states with pressure are observed in the Mn K-Edge spectra. A schematic pressure-temperature phase diagram is given for the small ion REMnO 3 system.

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“…However, some of the hexagonal compounds can also be synthesized as a metastable phase in the orthorhombic structure by either special chemical procedures 11 or high pressure synthesis. 12 The hexagonal phases of RMnO 3 show ferroelectricity below Curie temperatures between 590 and 1000 K and antiferromagnetic (AFM) transitions below 100 K with small but distinct anomalies in the dielectric constant at or below the magnetic transitions.1-4 Since symmetry arguments do not allow a direct coupling between the Mn magnetic order and the polarization in the hexagonal structure the observed magnetodielectric coupling has to be related to secondary interactions but a microscopic explanation of these effects is not yet available. Some work has been done to investigate possible magnetodielectric effects in the orthorhombic phases of RMnO 3 .…”

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confidence: 99%

Large magnetodielectric effects in orthorhombicHoMnO3andYMn
Lorenz
¹
,
Wang
²
,
Sun
³

et al. 2004
Phys. Rev. B

223

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We have found a remarkable increase (up to 60%) of the dielectric constant with the onset of magnetic order at 42 K in the metastable orthorhombic structures of YMnO 3 and HoMnO 3 that proves the existence of a strong magnetodielectric coupling in the compounds. Magnetic, dielectric, and thermodynamic properties show distinct anomalies at the onset of the incommensurate magnetic order and thermal hysteresis effects are observed around the lock-in transition temperature at which the incommensurate magnetic order locks into a temperature independent wave vector. The Mn 3+ spins and Ho 3+ moments both contribute to the magnetodielectric coupling. A large magnetodielectric effect was observed in HoMnO 3 at low temperature where the dielectric constant can be tuned by an external magnetic field resulting in a decrease of up to 8% at 7 T. By comparing data for YMnO 3 and HoMnO 3 the contributions to the coupling between the dielectric response and Mn and Ho magnetic moments are separated. The coupling between dielectric and magnetic properties recently observed in some manganites [1][2][3][4][5][6] and in other oxides 7,8 is of fundamental interest and of eminent significance for potential applications. The anomalies of dielectric (magnetic) properties at magnetic (ferroelectric) phase transitions and the possibility of tuning the dielectric constant (magnetization) by external magnetic (electric) fields open alternate perspectives in the basic understanding of the interesting materials and for the design of devices. The magnetodielectric effect can be explained by a spin-lattice coupling due to an increase of magnetic exchange energy when the magnetic ions shift their positions. 9,10 This effect is particularly strong close to or below a magnetic phase transition and may result in structural anomalies and a change of the dielectric properties.The rare earth manganites, RMnO 3 (R = rare earth metal), exhibit strong magnetic exchange interactions between the magnetic moments of the Mn 3+ ions as well as some of the magnetic R 3+ . Depending on the rare earth ionic size, RMnO 3 crystallizes in either hexagonal or orthorhombic (distorted perovskite) structure with the structural phase boundary between Ho and Dy. However, some of the hexagonal compounds can also be synthesized as a metastable phase in the orthorhombic structure by either special chemical procedures 11 or high pressure synthesis. 12 The hexagonal phases of RMnO 3 show ferroelectricity below Curie temperatures between 590 and 1000 K and antiferromagnetic (AFM) transitions below 100 K with small but distinct anomalies in the dielectric constant at or below the magnetic transitions.1-4 Since symmetry arguments do not allow a direct coupling between the Mn magnetic order and the polarization in the hexagonal structure the observed magnetodielectric coupling has to be related to secondary interactions but a microscopic explanation of these effects is not yet available. Some work has been done to investigate possible magnetodielectric effects in the orthorhombic...

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Magnetic properties of heavy-rare-earth orthomanganites

Cited by 80 publications

References 20 publications

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO₃ thin films

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO₃ thin films

High-pressure structural stability of multiferroic hexagonalRMnO3(R=Y, Ho, Lu)

Large magnetodielectric effects in orthorhombicHoMnO3andYMn
Lorenz
¹
,
Wang
²
,
Sun
³

et al. 2004
Phys. Rev. B

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Magnetic properties of heavy-rare-earth orthomanganites

Cited by 80 publications

References 20 publications

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO3 thin films

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO3 thin films

High-pressure structural stability of multiferroic hexagonalRMnO3(R=Y, Ho, Lu)

Large magnetodielectric effects in orthorhombicHoMnO3andYMnLorenz1, Wang2, Sun3 et al. 2004Phys. Rev. B

Contact Info

Product

Resources

About

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO₃ thin films

Dielectric anomaly and magnetic response of epitaxial orthorhombic YMnO₃ thin films

Large magnetodielectric effects in orthorhombicHoMnO3andYMn
Lorenz
¹
,
Wang
²
,
Sun
³

et al. 2004
Phys. Rev. B