Effect of A-site Fe substitution on the magnetic behavior of Dy2Ti2O7 spin ice

Yadav, Pramod Kumar; Harijan, Pappu Kumar; Tripathi, Abhishek Kumar; Upadhyay, Chandan

doi:10.1016/j.jmmm.2019.03.020

Cited by 7 publications

(6 citation statements)

References 30 publications

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“…Weak hybridization results in an emission peak at higher energy (shorter wavelength), an increase in the hybridization shifts the emission peak towards the longer wavelength side. Using an excitation wavelength of 455 nm, the luminescence spectra involve internal CTT within Dy-4f states at 517 nm ( 4 F 9/2 → 6 H 15/2 ), 686 nm ( 4 F 9/2 → 6 H 13/2 ), 734 nm ( 4 F 9/2 → 6 H 11/2 ), 782 nm ( 4 F 9/2 → 6 H 9/2 ) and 829 nm ( 4 F 9/2 → 6 H 7/2 ) through a cross-relaxation phenomenon since the spectra do not exhibit any modification with Mn inclusion as shown in figure 6 [9,40]. As discussed above, the possible mechanism and the energy level diagram involving the absorption and emission from the Dy 3+ , Mn 4+ , Ti 4+ and O 2− states are schematically shown in figure 7.…”

Section: Resultsmentioning

confidence: 92%

“…Moreover, their unusual chemical stability and flexibility to form solid solutions with several cations make them suitable as a host matrix for immobilizing and tuning of various physical properties. Fascinating magnetic properties had already been reported in context to various B site substituted pyrochlore oxides [3,[9][10][11][12][13][14][15][16][17][18]. Dy 2 Ti 2 O 7 belongs to a spin disordered system, the structure follows the prototype of a pyrochlore lattice (space group Fd 3m) which falls in the class of magnetically frustrated system [19,20].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Mn doping on the electronic and optical properties of Dy₂Ti₂O₇: a combined spectroscopic and theoretical study

Upadhyay

Shukla

Pandey

et al. 2023

J. Phys.: Condens. Matter

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Electronic and optical studies on Dy2Ti2−xMnxO7 (x = 0.00, 0.05, 0.10, 0.15, & 0.20) has been presented through both, theoretical (density functional theory calculations) and experimental (ultraviolet-visible absorption and photoluminescence emission spectroscopy) approaches. Density functional theory (DFT) calculations were employed considering the local density approximation (LDA) and LDA-1/2 for exchange-correlation interactions. Computed crystallographic parameters and energy band-gap using theoretical formulations are in good agreement with experimental results. The band-gap value obtained through the LDA-1/2 approach indicates insulated ground state of Dy2Ti2−xMnxO7 (x = 0.00, 0.05, 0.10, 0.15, 0.20) system. Experimentally obtained band gap value reduces from 3.82 eV to 2.45 eV with increase in positive chemical pressure as x increases from 0 to 0.20. Reduction in band gap value is attributed to the fact that there exists a lack of hybridization between the O-2p orbital and Ti-3d orbital, which is well corelated with the crystallographic data. Jahn-Teller effect is likely to be responsible for the presence of a mixed state of Mn (explained using x-ray photoelectron spectroscopy results), resulting in the intermediate Mn state between the valence band (VB) and the conduction band (CB) with immediate inclusion of Mn at Ti site in Dy2Ti2−xMnxO7 system.

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Section: Resultsmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Effect of Mn doping on the electronic and optical properties of Dy₂Ti₂O₇: a combined spectroscopic and theoretical study

Upadhyay

Shukla

Pandey

et al. 2023

J. Phys.: Condens. Matter

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“…For the sample synthesis, we used the standard thermochemical solid-state reaction technique [23,24]. Samples synthesis, phase purity, and structural details have already been reported in [22]. Low-temperature magnetic measurements were performed with Magnetic Properties Measurement System (MPMS-3)® (Quantum Design, Inc.) USA.…”

Section: Methodsmentioning

confidence: 99%

“…Unlike Dy 3+ ion, the substituted Fe 3+ ion's spin is associated with its outermost d-orbital, which participates in Fe3d-O2p covalent bonding. Due to this participation, crystal field-induced spin constrained along the local 〈111〉 axis is not applicable on the substituted Fe spin, and it behaves non-Ising-like without affecting the neighboring Dy 3+ Ising spin [22]. The substitution of Fe notably affects the cooperative spin dynamics in different measurement conditions, underscoring the crucial role of the local defects in the emerging memory effect in DTO, discussed in detail.…”

Section: Introductionmentioning

confidence: 99%

Influence of local defects in the generation of memory effect in Dy₂Ti₂O₇ compound: Fe-doped study

Yadav,

Upadhyay,

Kumar

et al. 2024

Phys. Scr.

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The study of defect-induced effects in functional materials is high-priority research for the miniaturization of smart devices. To elucidate the influence of local defects stemming from intrinsic or extrinsic factors on the enigmatic behavior of cooperative spin dynamics, we investigated the Dy2-xFexTi2O7 compound within a narrow Fe substitution range (x = 0–0.15). Our experimental findings unequivocally demonstrate that the dynamic response of cooperative spins and the emergence of anomalous memory effect are intricately linked to local defects. Depending on the nature and dynamics of these defects, the dynamic response of cooperative spins undergoes alteration. Notably, observed anomalous effect becomes more pronounced in scenarios characterized by slower defect dynamics and when cooperative spins are further from equilibrium. The emergence and sensitivity of thermomagnetic hysteresis (memory effect) to cooperative spin dynamics and external stimuli underscore the richness of Dy2Ti2O7 as a material for captivating physics investigations.

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“…High-quality polycrystalline Dy 2 Ti 2 O 7 (DTO) and Ho 2 Ti 2 O 7 (HTO) samples have been used for the magnetic and dielectric measurements. Samples synthesis, phase purity, and their structural details have already been reported in [18][19][20]. Magnetic measurements are performed using Magnetic Properties Measurement System (MPMS-3) ® (Quantum Design, Inc.) USA.…”

Section: Methodsmentioning

confidence: 99%

Emergence of field-induced memory effect in spin ices

Yadav,

Upadhyay,

Kumar

et al. 2023

J. Phys.: Condens. Matter

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Out-of-equilibrium investigation of strongly correlated materials deciphers the hidden equilibrium properties. Herein, we have investigated the out-of-equilibrium magnetic properties of polycrystalline Dy2Ti2O7 and Ho2Ti2O7 spin ices. Our experimental findings reveal the emergence of magnetic field-induced anomalous hysteresis observed solely in temperature-and magnetic field-dependent AC susceptibility measurements. The observed memory effect (anomalous thermomagnetic hysteresis) exhibits a strong dependence on both thermal and non-thermal driving variables. Owing to the non-collinear spin structure, the applied DC bias magnetic field produces quenched disorder sites in the cooperative Ising spin matrix and suppresses the spin-phonon coupling. These quench disorders create a dynamic spin correlation, having slow spin relaxation and quick decay time, which additionally contribute to AC susceptibility. The initial conditions and measurement protocol decide the magnitude and sign of this dynamical term contributing to AC susceptibility. It is being suggested that such out-of-equilibrium properties arise from the combined influences of geometric frustration, disorder, and the cooperative nature of spin dynamics exhibited by these materials.

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Effect of A-site Fe substitution on the magnetic behavior of Dy2Ti2O7 spin ice

Cited by 7 publications

References 30 publications

Effect of Mn doping on the electronic and optical properties of Dy₂Ti₂O₇: a combined spectroscopic and theoretical study

Effect of Mn doping on the electronic and optical properties of Dy₂Ti₂O₇: a combined spectroscopic and theoretical study

Influence of local defects in the generation of memory effect in Dy₂Ti₂O₇ compound: Fe-doped study

Emergence of field-induced memory effect in spin ices

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Effect of A-site Fe substitution on the magnetic behavior of Dy2Ti2O7 spin ice

Cited by 7 publications

References 30 publications

Effect of Mn doping on the electronic and optical properties of Dy2Ti2O7: a combined spectroscopic and theoretical study

Effect of Mn doping on the electronic and optical properties of Dy2Ti2O7: a combined spectroscopic and theoretical study

Influence of local defects in the generation of memory effect in Dy2Ti2O7 compound: Fe-doped study

Emergence of field-induced memory effect in spin ices

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Resources

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Effect of Mn doping on the electronic and optical properties of Dy₂Ti₂O₇: a combined spectroscopic and theoretical study

Effect of Mn doping on the electronic and optical properties of Dy₂Ti₂O₇: a combined spectroscopic and theoretical study

Influence of local defects in the generation of memory effect in Dy₂Ti₂O₇ compound: Fe-doped study