Engel-Vosko GGA calculations of the structural, electronic and optical properties of LiYO 2

Muhammad, Nisar; Khan, Afzal; Khan, Sarfraz; Siraj, Muhammad; Shah, Syed Sarmad Ali; Murtaza, G.

doi:10.1016/j.physb.2017.06.055

Cited by 12 publications

(7 citation statements)

References 31 publications

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“…LiYO 2 crystallizes in two crystallographic phases: a low-temperature monoclinic phase ( P21/c space group, LT) and a high-temperature tetragonal phase ( I41/amd space group, HT) (Figure a). − The phase transition temperature significantly depends on the material’s morphology (in the case of LiYO 2 single crystal, the phase transition was found at 373 K, while for nanomaterial with an average particle size of ∼50 nm, it occurs around 293 K), and the type and concentration of dopant ions. , Regardless of the temperature, the structural transition results in a change in the size of the unit cell from a = 6.1493(8) Å, b = 6.1500(10) Å, c = 6.2494(2) Å, β = 119.091(5)° to a = 4.4468(9) Å, c = 10.372(22) Å and the point symmetry of Y 3+ ions from C 2 to D 2d . The change in the point symmetry of the Y 3+ cation is particularly significant as lanthanide dopant ions substitute for the Y 3+ cation, and the point symmetry significantly modifies the spectroscopic properties of the dopant.…”

Section: Resultsmentioning

confidence: 99%

“…An excellent example of such host material is LiYO 2 , undergoing a structural phase transition from a monoclinic (low-temperature phase) to a tetragonal structure (high-temperature phase) around room temperature, resulting in an alteration of the point symmetry of the Y 3+ ion from C 2 to D 2d . 19 − 23 Previous studies have underscored the success of this strategic approach, yielding very high relative thermal sensitivities surpassing 10% K –1 .…”

Section: Introductionmentioning

confidence: 99%

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The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO₂:Er³⁺,Yb³⁺

Marciniak,

Piotrowski,

Szymczak

et al. 2024

ACS Appl. Mater. Interfaces

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In response to the ongoing quest for new, highly sensitive upconverting luminescent thermometers, this article introduces, for the first time, upconverting luminescent thermometers based on thermally induced structured phase transitions. As demonstrated, the transition from the low-temperature monoclinic to the high-temperature tetragonal structures of LiYO2:Yb3+,Er3+ induces multifaceted modification in the spectroscopic properties of the examined material, influencing the spectral positions of luminescence bands, energy gap values between thermally coupled energy levels, and the red-to-green emission intensities ratio. Moreover, as illustrated, both the color of the emitted light and the phase transition temperature (from 265 K, for LiYO2:Er3+, 1%Yb3+, to 180 K, for 10%Yb3+), and consequently, the thermometric parameters of the luminescent thermometer can be modulated by the concentration of Yb3+ sensitizer ions. Establishing a correlation between the phase transition temperature and the mismatch of ion radii between the host material and dopant ions allows for smooth adjustment of the thermometric performance of such a thermometer following specific application requirements. Three different thermometric approaches were investigated using thermally coupled levels (S R = 1.8%/K at 180 K for 1%Yb3+), green to red emission intensities ratio (S R = 1.5%/K at 305 K for 2%Yb3+), and single band ratiometric approach (S R = 2.5%/K at 240 K for 10%Yb3+). The thermally induced structural phase transition in LiYO2:Er3+,Yb3+ has enabled the development of multiple upconverting luminescent thermometers. This innovative approach opens avenues for advancing the field of luminescence thermometry, offering enhanced relative thermal sensitivity and adaptability for various applications.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO₂:Er³⁺,Yb³⁺

Marciniak,

Piotrowski,

Szymczak

et al. 2024

ACS Appl. Mater. Interfaces

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“…Consequently, the local point symmetry of the Y 3+ ions substituted by the lanthanide (Ln 3+ ) dopant ions changes from the C 2 to D 2d . [27,[33][34][35] Since the local point symmetry determines the strength of crystal field splitting of the multiplets of the luminescent ions into Stark sublevels, the observed temperature-driven phase transition significantly modifies the optical properties of the LiYO 2 :Nd 3+ phosphor. To trace and understand this structural phase transition the XRD patterns were measured as a function of temperature (Figure 1b).…”

Section: Resultsmentioning

confidence: 99%

“…As confirmed previously, the morphology and reduction in particle size of the phosphor may lead to a decrease in the temperature of the phase transition. [ 27,34 ] Hence, the peak in the DSC curve localized at higher temperature can be ascribed to the larger particles, while the low temperature peak for the smaller counterparts. Moreover, some distribution of the particles size within the particular group of particles can also be found, which explains the width of the individual DSC peaks.…”

Section: Resultsmentioning

confidence: 99%

Phase Transition‐Driven Highly Sensitive, NIR–NIR Band‐Shape Luminescent Thermometer Based on LiYO₂:Nd³⁺

Marciniak

Piotrowski

Drozd

et al. 2022

Advanced Optical Materials

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reliability of temperature readout, which is achievable by 1) increasing the luminescence brightness and/or 2) increasing the relative sensitivity of the luminescent thermometer. [5,6,9] For the materials that are currently most intensively used and studied in luminescence thermometry, i.e., inorganic materials doped with luminescent ions, two strategies are currently employed, 1) the utilization of singly doped materials; and 2) exploitation of Co-doped materials. [10][11][12][13][14][15][16][17][18][19][20][21][22] While the latter approach yields very promising results, there is a significant risk that scaling-up the synthesis of materials to amounts required by industry, the inhomogeneous distribution of dopant ions and their clustering may occur. This may modify the thermometric performance of the phosphor and lead to an unreliable temperature readout. [5,9] On the other hand, for ratio metric temperature measurements based on phosphors doped with one type of luminescent dopant, luminescence intensity ratio from thermally coupled levels is used as a thermometric parameter. [9,[23][24][25] In this approach, the relative sensitivity is proportional to the energy difference ΔE between these levels. [26] It is well known that above ΔE = 2000 cm -1 , the thermal energy required to populate the higher-laying state becomes too high to obtain intense emission. [26] Hence, a further increase in sensitivity is difficult to achieve. In response to the above-mentioned limitations and the requirement to develop luminescent thermometers based on single ion luminescence with high relative sensitivity, the application of materials exhibiting temperature-induced firstorder phase transitions has recently been proposed. [27] In this work, a new luminescent thermometer, whose operating principle exploits a temperature-induced first-order phase transition, is proposed. Although luminescent thermometers using structural phase transition have been described in the literature before, the main limitation of these thermometers is their relatively low sensitivity. [28,29] Therefore, here, LiYO 2 :Nd 3+ nanocrystals have been synthesized for which the temperature increase above ≈290 K induces a structural change from monoclinic (P2 1 /c, Z = 4) to tetragonal (I4 1 /amd, Z = 4) and thus a change in the point symmetry of the crystallographic site of Y 3+ (occupied by the luminescent Nd 3+ ions) from C 2 to D 2d . [30][31][32][33] This symmetry change clearly affects the energy of the Stark levels of the 4 I J mutiplets (Figure S3, Supporting Information) Almost all existing luminescent thermometers rely on the temperaturedependent processes such as multi-phonon relaxation and phonon-assisted energy transfers, thermal population, or coupling between energy levels of ground and excited states of luminescent species (lanthanides, transition metals, quantum dots, fluorescent molecules, etc.). Although such phenomena are in principle suitable for straightforward calibration, aiming to offer high temperature sensitivity, high temperature resol...

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“…Various 2D materials with characteristics * Author to whom any correspondence should be addressed. of metals, semiconductors, and insulators have been prepared and predicted [8][9][10][11][12]. Among them, transition metal sulfides and some others have been widely studied for their potential electronic and optical applications due to their appropriate band gaps [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

First-principles study of the electronic and optical properties of two-dimensional PtS₂/GaS van der Waals heterostructure

Zhu,

Wang

2024

J. Phys. D: Appl. Phys.

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Heterostructures based on two-dimensional (2D) materials have received increasing attention due to their extraordinary properties and application potential. In this paper, the electronic and optical properties of the PtS2/GaS van der Waals (vdW) heterostructure as well as the effects of biaxial strain and external electric field are systematically investigated based on first-principles calculations. The PtS2/GaS vdW heterostructure has an interlayer distance of 3.01 Å and is a type-Ⅱ semiconductor of band gap 1.54 eV. Large optical absorption coefficients are observed in both the ultraviolet and the visible regions. Furthermore, its band structure can be effectively tuned by applying biaxial strain and external electric field. The transition between the type-Ⅱ and type-I band alignments can be realized. The absorption spectra and their peaks can be then manipulated effectively by applying biaxial strain with good stability under external electric field. The predicted tunable electronic properties and unique optical absorption properties suggests promising potential for the application of the PtS2/GaS vdW heterostructure in future optoelectronic nanodevices.

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Engel-Vosko GGA calculations of the structural, electronic and optical properties of LiYO 2

Cited by 12 publications

References 31 publications

The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO₂:Er³⁺,Yb³⁺

The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO₂:Er³⁺,Yb³⁺

Phase Transition‐Driven Highly Sensitive, NIR–NIR Band‐Shape Luminescent Thermometer Based on LiYO₂:Nd³⁺

First-principles study of the electronic and optical properties of two-dimensional PtS₂/GaS van der Waals heterostructure

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Engel-Vosko GGA calculations of the structural, electronic and optical properties of LiYO 2

Cited by 12 publications

References 31 publications

The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO2:Er3+,Yb3+

The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO2:Er3+,Yb3+

Phase Transition‐Driven Highly Sensitive, NIR–NIR Band‐Shape Luminescent Thermometer Based on LiYO2:Nd3+

First-principles study of the electronic and optical properties of two-dimensional PtS2/GaS van der Waals heterostructure

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The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO₂:Er³⁺,Yb³⁺

The Butterfly Effect: Multifaceted Consequences of Sensitizer Concentration Change in Phase Transition-based Luminescent Thermometer of LiYO₂:Er³⁺,Yb³⁺

Phase Transition‐Driven Highly Sensitive, NIR–NIR Band‐Shape Luminescent Thermometer Based on LiYO₂:Nd³⁺

First-principles study of the electronic and optical properties of two-dimensional PtS₂/GaS van der Waals heterostructure