Electronic, magnetic, optical and thermoelectric properties of Ca2Cr1−xNixOsO6 double perovskites

Bhandari, Shalika Ram; Yadav, Dinesh Kumar; Belbase, Bishnu Prasad; Zeeshan, Mohd; Sadhukhan, Banasree; P., D.; Thapa, R. K.; Kaphle, Gopi Chandra; Ghimire, Madhav Prasad

doi:10.1039/c9ra10775d

“…The thermoelectric performance of a material is given by dimensionless parameter known as figure of merit (ZT) given by ZT ¼ S 2 σT k e þk l ð Þ , where S, σ, T, k e , and k l represent the Seebeck coefficient, electrical conductivity, temperature, electrical thermal conductivity, and lattice thermal conductivity, respectively. 45 A material with ZT value close to unity is considered to be good thermoelectric material. The high ZT value can only be obtained when there is a ultra-low thermal conductivity and high electrical conductivity.…”

Section: Introductionmentioning

confidence: 99%

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs ₂ Tl(As/Sb)I ₆

Sk

¹

,

Ghosh

²

2022

Intl J of Energy Research

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Summary In this article, we have systematically investigated the structural, electronic, optical, and thermoelectric properties of Cs2Tl(As/Sb)I6. The obtained negative formation energy along without the presence of imaginary phonon frequency confirmed the thermodynamic stability of Cs2Tl(As/Sb)I6. In addition, the new mBJ approach showed the direct band gap value of 1.10 and 1.33 eV for Cs2TlAsI6 and Cs2TlSbI6, respectively. Furthermore, the dispersed direct band nature of Cs2Tl(As/Sb)I6 leads to their outshining optical properties such as higher‐order (105 cm−1) absorption coefficient, appreciable optical conductivity, and low reflectivity. Moreover, the higher figure of merit values of Cs2Tl(As/Sb)I6 are resulted from their ultra‐low thermal conductivity and high electrical conductivity. Thus, Cs2Tl(As/Sb)I6 are predicted to be potential photovoltaic and thermoelectric materials.

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“…Since both optical and transport properties of bandgap materials are central to determining their utilization in solar radiation‐based devices, it is intuitive to examine these properties simultaneously. For instance, Bhandari et al 22 studied Ca 2 Cr 1‐x Ni x OsO 6 double perovskites to study their electronic and magnetic characteristics along with optical and thermoelectric traits using density functional theory (DFT). The results revealed that the prepared double perovskite was ferrimagnetic with a small bandgap (eg, ~0.6 eV) and is optically isotropic.…”

Section: Introductionmentioning

confidence: 99%

Ab‐initio study of opto‐electronic and thermoelectric properties of direct bandgap double perovskites Rb ₂ XGaBr ₆ (XNa, K)

Haq

¹

,

Mustafa

²

,

Amin

³

et al. 2021

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Double perovskite halides are potential materials for the production of renewable energy that could meet the global demands for resolving energy shortage issues. In this study, we systematically investigate the Rb 2 XGaBr 6 (X Na, K) double perovskites using the full-potential linearized augmented plane wave (FP-LAPW+lo) method of density functional theory. The thermodynamic as well as the structural stabilities of the studied materials have been confirmed from the calculated formation energy and Goldsmith tolerance factor (0.89 and 0.92). On the other hand, the calculated Pugh's ratio shows the ductile mechanical nature of the studied materials. The calculated electronic bandgaps of 2.2 eV/1.90 eV for Rb 2 Na/KGaBr 6 lies is in the visible region, which indicated the potential application of these materials in solar cells. The electronic properties of the two compounds are studied using the electronic density of states and the complex dielectric functions are used to evaluate optical properties. Our calculated results clearly indicate the optimum absorption of light in visible regions which depicts the potential of these materials for optoelectronic devices. The thermoelectric properties of the two Rb 2 XGaBr 6 (X Na, K) double perovskites are also studied in terms of thermal and electrical conductivity and the Seebeck coefficient. K E Y W O R D Sdensity functional theory, direct band gap double perovskite, figure of merit, mechanical characteristics, opto-electronic devices

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“…As it is experimentally and theoretically established that DPOs are considered beneficial candidates for electron and hole-doping at A or B site, aiming to obtain optimized physical properties that were not present in their undoped form 31 – 47 . For example, in a widely studied DPO, electron doping which is obtained by partial replacement of with results in the enhancement of 31 – 34 .…”

Section: Introductionmentioning

confidence: 99%

“…It is also predicted that extra electrons go to the Mo 4 d orbitals, which are responsible for metallicity in these doped systems. Very recently, Bhandari et al 47 , theoretically demonstrated that electron doping at B site (i.e., 50% Ni-doping at Cr site) in a FiM Mott-insulator gives rise to a nearly compensated HM state which has potential applications for spintronic devices. In this case, Ni is in a 2 state with configurations and when it is replaced with Cr of charge of having a configuration of , therefore, five extra electrons added to the system which results in an HM state.…”

Section: Introductionmentioning

confidence: 99%

Insulator-to-half metal transition and enhancement of structural distortions in $$\text {Lu}_2 \text {NiIrO}_6$$ double perovskite oxide via hole-doping

Nazir

¹

2021

Sci Rep

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Using density functional theory calculations, we found that recently high-pressure synthesized double perovskite oxide $$\text {Lu}_2 \text {NiIrO}_6$$ Lu 2 NiIrO 6 exhibits ferrimagnetic (FiM) Mott-insulating state having an energy band gap of 0.20 eV which confirms the experimental observations (Feng et al. in Inorg Chem 58:397–404, 2019). Strong antiferromagnetic superexchange interactions between high-energy half-filled $$\text {Ni}^{+2}$$ Ni + 2 -$$e_g^2\uparrow$$ e g 2 ↑ and low-energy partially filled $$\text {Ir}^{+4}\,t_{2g}^3\uparrow t_{2g}^2\downarrow$$ Ir + 4 t 2 g 3 ↑ t 2 g 2 ↓ orbitals, results in a FiM spin ordering. Besides, the effect of 3d transition metal (TM = Cr, Mn, and Fe) doping with 50% concentration at Ni sites on its electronic and magnetic properties is explored. It is established that smaller size cation-doping at the B site enhances the structural distortion, which further gives strength to the FiM ordering temperature. Interestingly, our results revealed that all TM-doped structures exhibit an electronic transition from Mott-insulating to a half-metallic state with effective integral spin moments. The admixture of Ir 5d orbitals in the spin-majority channel are mainly responsible for conductivity, while the spin minority channel remains an insulator. Surprisingly, a substantial reduction and enhancement of spin moment are found on non-equivalent Ir and oxygen ions, respectively. This leads the Ir ion in a mixed-valence state of $$+4$$ + 4 and $$+5$$ + 5 in all doped systems having configurations of $$5d^5$$ 5 d 5 ($$t_{2g}^3\uparrow t_{2g}^2\downarrow$$ t 2 g 3 ↑ t 2 g 2 ↓ ) and $$5d^4$$ 5 d 4 ($$t_{2g}^2\uparrow t_{2g}^2\downarrow$$ t 2 g 2 ↑ t 2 g 2 ↓ ), respectively. Hence, the present work proposes that doping engineering with suitable impurity elements could be an effective way to tailor the physical properties of the materials for their technological potential utilization in advanced spin devices.

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Electronic, magnetic, optical and thermoelectric properties of Ca₂Cr_1−xNi_xOsO₆ double perovskites

Abstract: With the help of density functional theory calculations, we explored the recently synthesized double perovskite material Ca2CrOsO6 and found it to be a ferrimagnetic insulator with a band gap of ∼0.6 eV.

Cited by 46 publications

References 74 publications

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs ₂ Tl(As/Sb)I ₆

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs ₂ Tl(As/Sb)I ₆

Ab‐initio study of opto‐electronic and thermoelectric properties of direct bandgap double perovskites Rb ₂ XGaBr ₆ (XNa, K)

Insulator-to-half metal transition and enhancement of structural distortions in $$\text {Lu}_2 \text {NiIrO}_6$$ double perovskite oxide via hole-doping

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Electronic, magnetic, optical and thermoelectric properties of Ca2Cr1−xNixOsO6 double perovskites

Abstract: With the help of density functional theory calculations, we explored the recently synthesized double perovskite material Ca2CrOsO6 and found it to be a ferrimagnetic insulator with a band gap of ∼0.6 eV.

Cited by 46 publications

References 74 publications

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs 2 Tl(As/Sb)I 6

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs 2 Tl(As/Sb)I 6

Ab‐initio study of opto‐electronic and thermoelectric properties of direct bandgap double perovskites Rb 2 XGaBr 6 (XNa, K)

Insulator-to-half metal transition and enhancement of structural distortions in $$\text {Lu}_2 \text {NiIrO}_6$$ double perovskite oxide via hole-doping

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Product

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Electronic, magnetic, optical and thermoelectric properties of Ca₂Cr_1−xNi_xOsO₆ double perovskites

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs ₂ Tl(As/Sb)I ₆

First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs ₂ Tl(As/Sb)I ₆

Ab‐initio study of opto‐electronic and thermoelectric properties of direct bandgap double perovskites Rb ₂ XGaBr ₆ (XNa, K)