| Keywords [eng] |
magnesium whitlockite, manganese whitlockite, low-temperature synthesis, dissolution-precipitation method, hydrothermal conditions, thermal stability studies, studies on magnetic properties, paramagnetic properties, XRD, BET, SEM, Rietveld refinement, thermogravimetric analysis, FTIR spectroscopy, Raman Spectroscopy. |
| Abstract [eng] |
In the present work, magnesium and manganese whitlockite were synthesized by dissolution-precipitation process under hydrothermal conditions and low-temperature synthesis respectively. Synthesis conditions such as temperature, pH and reaction time were thoroughly studied and optimized. It was demonstrated that pure-phase magnesium whitlockite can be synthesized hydrothermally in 3h at 160 ℃, whereas pristine manganese whitlockite can be obtained by low-temperature synthesis at 75 ℃ at the same reaction time. Thermal stability studies revealed that both magnesium and manganese are thermally unstable compounds and decomposed upon heat treatment with the formation of β Ca3(PO4), α-Ca2P2O7, and β-Ca2P2O7 phases. Studies on magnetic properties demonstrated the paramagnetic nature of the synthesized manganese whitlockite both at 5 K and room temperatures. Synthesized compounds were analyzed by X-ray diffraction and Rietveld refinement, Fourier-Transform Infrared and Raman spectroscopies, Scanning Electron Microscopy, Brunauer–Emmett–Teller (BET) surface area analysis. In addition, studies in magnetic properties and thermogravimetric measurements were performed Therefore, cost-effective and rapid synthesis methods of magnesium and manganese whitlockite were developed. To the best of our knowledge, manganese whitlockite was synthesized for the first time in this work. |
