Spinels are an emerging class of advanced technological materials for spintronic,energy harvesting,and water-splitting applications.In this work,we explored the electronic,magnetic,optical,and transport properties of ...Spinels are an emerging class of advanced technological materials for spintronic,energy harvesting,and water-splitting applications.In this work,we explored the electronic,magnetic,optical,and transport properties of CaCe_(2)(S/Se)_(4)by density functional theory based on the Wien2k code.The energy released during optimization in ferromagnetic and antiferromagnetic states confirms that the ferromagnetic state is stable,which is further verified by negative formation energy.Heisenberg model and density of states report the Curie temperature and spin polarization.Half metallic ferromagnetism(HMF)regarding hybridization,crystal fields,exchange ene rgies,and double exchange mechanisms is discussed.The transfer of magnetic moments from Ce to Ca and S/Se and interstitial sites ensure the role of spin of electrons rather than clustering.Mo reover,the optical prope rties are addressed by dielectric constants,absorption,refraction,and optical loss.The first absorption peaks exist in infrared zone;others fall in visible to ultraviolet zones.The spin-up(↑)and spin-down(↓)channel thermoelectric factors combine and report the performance by conductivities,Seebeck coefficient,and power factor.Therefore,the studied materials'optical and thermoelectric behaviours will allow researchers to realize them for technological applications.展开更多
In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were investigated.The energy difference in ferromagnetic and antiferromagnetic states reveals the stabi...In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were investigated.The energy difference in ferromagnetic and antiferromagnetic states reveals the stability of MgPm_(2)(S/Se)_(4) in the ferromagnetic states.The co mputation of enthalpy of formation also ascertains thermodynamic stability of crystal structure.Spin-dependent band structure and density of states analysis reveal ferromagnetic semiconducting character showing different electronic behavior in both spin channels.The room temperature ferromagnetism,spin polarization and Curie temperature are estimated from exchange energies analysis.In addition,exchange constants(N_(0)α and N_(0)β),exchange energy Δ_(x)(pd),crystal ifeld energy,and double exchange mechanism were studied to explore the magnetic response.Likewise,the electrical conductivity,thermal conductivity,Seebeck co-efficient,and power factor show effect on electrons spin and their potential for thermoelectric devices.展开更多
This research presents a detailed ab initio density functional theory(DFT)analysis on magnetic,thermoelectric,and optoelectronic properties of CaPr_(2)(S/Se)_(4) executed by Wien2k and Boltztrap2 packages for spintron...This research presents a detailed ab initio density functional theory(DFT)analysis on magnetic,thermoelectric,and optoelectronic properties of CaPr_(2)(S/Se)_(4) executed by Wien2k and Boltztrap2 packages for spintronic energy applications.The density of states,optimization energy,and negative formation energy all support the stability of the ferromagnetic state.The spin polarization density and Curie temperature(310 and 289 K)are also reported.In addition,the double exchange model,hybridization,density of states,band structures,exchange constants,exchange energies,and crystal field energies are addressed to ensure ferromagnetism by the spin of electrons.The magnetic moment of Pr shifts to Ca and S/Se sites,revealing that ferromagnetism is due to electron spin,not clustering of Pr magnetic ions.Thermoelectrics were evaluated by electrical conductivity(σ),thermal conductivity(k_(e)),Seebeck coefficient(S),power factor(S^(2)),and figures of merit(ZT).The room tempe rature values of S(0.169,0.183 mV/K)and ZT(0.76,0.90)increase their thermoelectric performance.Furthermore,dielectric function,refractive index,absorption coefficientα(ω),reflectivity R(ω),and other parameters are demonstrated in detail.Therefore,researchers can develop materials with the potential for spintronic and energy harvesting.展开更多
基金the Deanship of Research and Graduate Studies at King Khalid University,Saudi Arabia for funding this work through Large Research Project under grant number RGP2/630/45。
文摘Spinels are an emerging class of advanced technological materials for spintronic,energy harvesting,and water-splitting applications.In this work,we explored the electronic,magnetic,optical,and transport properties of CaCe_(2)(S/Se)_(4)by density functional theory based on the Wien2k code.The energy released during optimization in ferromagnetic and antiferromagnetic states confirms that the ferromagnetic state is stable,which is further verified by negative formation energy.Heisenberg model and density of states report the Curie temperature and spin polarization.Half metallic ferromagnetism(HMF)regarding hybridization,crystal fields,exchange ene rgies,and double exchange mechanisms is discussed.The transfer of magnetic moments from Ce to Ca and S/Se and interstitial sites ensure the role of spin of electrons rather than clustering.Mo reover,the optical prope rties are addressed by dielectric constants,absorption,refraction,and optical loss.The first absorption peaks exist in infrared zone;others fall in visible to ultraviolet zones.The spin-up(↑)and spin-down(↓)channel thermoelectric factors combine and report the performance by conductivities,Seebeck coefficient,and power factor.Therefore,the studied materials'optical and thermoelectric behaviours will allow researchers to realize them for technological applications.
基金funded by the Princess Nourah bint Abdulrahman University Researchers Supporting Project(PNURSP2023R29)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabiathe Deanship of Scientific Research at King Khalid University,SaudiArabia for funding this work through Large Groups Project(L.R.G.P2/431/44)。
文摘In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were investigated.The energy difference in ferromagnetic and antiferromagnetic states reveals the stability of MgPm_(2)(S/Se)_(4) in the ferromagnetic states.The co mputation of enthalpy of formation also ascertains thermodynamic stability of crystal structure.Spin-dependent band structure and density of states analysis reveal ferromagnetic semiconducting character showing different electronic behavior in both spin channels.The room temperature ferromagnetism,spin polarization and Curie temperature are estimated from exchange energies analysis.In addition,exchange constants(N_(0)α and N_(0)β),exchange energy Δ_(x)(pd),crystal ifeld energy,and double exchange mechanism were studied to explore the magnetic response.Likewise,the electrical conductivity,thermal conductivity,Seebeck co-efficient,and power factor show effect on electrons spin and their potential for thermoelectric devices.
文摘This research presents a detailed ab initio density functional theory(DFT)analysis on magnetic,thermoelectric,and optoelectronic properties of CaPr_(2)(S/Se)_(4) executed by Wien2k and Boltztrap2 packages for spintronic energy applications.The density of states,optimization energy,and negative formation energy all support the stability of the ferromagnetic state.The spin polarization density and Curie temperature(310 and 289 K)are also reported.In addition,the double exchange model,hybridization,density of states,band structures,exchange constants,exchange energies,and crystal field energies are addressed to ensure ferromagnetism by the spin of electrons.The magnetic moment of Pr shifts to Ca and S/Se sites,revealing that ferromagnetism is due to electron spin,not clustering of Pr magnetic ions.Thermoelectrics were evaluated by electrical conductivity(σ),thermal conductivity(k_(e)),Seebeck coefficient(S),power factor(S^(2)),and figures of merit(ZT).The room tempe rature values of S(0.169,0.183 mV/K)and ZT(0.76,0.90)increase their thermoelectric performance.Furthermore,dielectric function,refractive index,absorption coefficientα(ω),reflectivity R(ω),and other parameters are demonstrated in detail.Therefore,researchers can develop materials with the potential for spintronic and energy harvesting.
