Ramkrushna Yerojwar - Academia.edu (original) (raw)

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Papers by Ramkrushna Yerojwar

Zenodo (CERN European Organization for Nuclear Research), Apr 30, 2023

The interaction of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) metal ions with 5-ethoxy ... more The interaction of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) metal ions with 5-ethoxy carbonyl-4-(4-chloro phenyl)-6-methyl-3,4-dihydropyrimidine-2(1H)-0ne (ligand-1) and 5-ethoxy carbonyl-4-(4-fluro phenyl)-6-methyl-3,4-dihydropyrimidine-2(1H)-0ne (ligand-2) have been investigated by pH-metric technique at 0.1 M ionic strength at 29 ± 0.1 ºC in 70 % THF-water mixture. The data obtained were used to estimate the values of proton-ligand stability constant (pK) and metal-ligand stability constant log K. It is observed that La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) metal ions forms 1:1 and 1:2 complexes with all the ligands. Also the prepapred complexes were studied spectrophotometrically. The stability constants have beeninvestigated in a 70% THF-aqueous mixture by the Job's continuous variation method. The results obtained of stability constants are in good concordance with the values of real stability constant by pH metric technique.

JOURNAL OF CHARACTERIZATION

Using the combustion method, red emitting Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were sy... more Using the combustion method, red emitting Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were synthesized. The properties of photoluminescence were also studied. The red (614 nm) emission from Sr4Al14O25:Eu 3+ phosphor, at excitation 394 nm. The excitation peak was around 404 nm and was attributed to 6 H5/2→ 4 F7/2, while the emission spectrum had emission peaks at 565 nm and 603 nm for Sr4Al14O25:Sm 3+ phosphor. Furthermore, the chromaticity coordinates of Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were found in the red region (0.677, 0.322) and (0.640, 0.359) by the Commission International de l'Eclairage respectively. According to the current findings, Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors can be used as a red emitting phosphor in near-ultraviolet (n-UV) based w-LEDs.

Zenodo (CERN European Organization for Nuclear Research), Apr 30, 2023

The interaction of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) metal ions with 5-ethoxy ... more The interaction of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) metal ions with 5-ethoxy carbonyl-4-(4-chloro phenyl)-6-methyl-3,4-dihydropyrimidine-2(1H)-0ne (ligand-1) and 5-ethoxy carbonyl-4-(4-fluro phenyl)-6-methyl-3,4-dihydropyrimidine-2(1H)-0ne (ligand-2) have been investigated by pH-metric technique at 0.1 M ionic strength at 29 ± 0.1 ºC in 70 % THF-water mixture. The data obtained were used to estimate the values of proton-ligand stability constant (pK) and metal-ligand stability constant log K. It is observed that La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) metal ions forms 1:1 and 1:2 complexes with all the ligands. Also the prepapred complexes were studied spectrophotometrically. The stability constants have beeninvestigated in a 70% THF-aqueous mixture by the Job's continuous variation method. The results obtained of stability constants are in good concordance with the values of real stability constant by pH metric technique.

JOURNAL OF CHARACTERIZATION

Using the combustion method, red emitting Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were sy... more Using the combustion method, red emitting Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were synthesized. The properties of photoluminescence were also studied. The red (614 nm) emission from Sr4Al14O25:Eu 3+ phosphor, at excitation 394 nm. The excitation peak was around 404 nm and was attributed to 6 H5/2→ 4 F7/2, while the emission spectrum had emission peaks at 565 nm and 603 nm for Sr4Al14O25:Sm 3+ phosphor. Furthermore, the chromaticity coordinates of Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors were found in the red region (0.677, 0.322) and (0.640, 0.359) by the Commission International de l'Eclairage respectively. According to the current findings, Sr4Al14O25:Eu 3+ and Sr4Al14O25:Sm 3+ phosphors can be used as a red emitting phosphor in near-ultraviolet (n-UV) based w-LEDs.