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您的检索式：作者名="Radovan DIMITRIJEVIC"
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| 1 | Crystal Structure and Chemical Composition of Ludwigite from Vranovac Ore Deposit (Boranja Mountain,Serbia)显示文摘The crystal structure of ludwigite from Vranovac ore deposit (Boranja Mt., Serbia) was refined using the X-ray powder diffraction (XRPD) Rietveld method in the space group Pbam to a final RB=7.45% and RF=5.26%. It has the unit cell dimensions of: a=9.2515(2) ; b=12.3109(2) ; c=3.03712(7) ; and V=345.91(1) 3. The calculated distances and angles are mostly in good agreement with the Mg2+-Fe2+ substitutions across the M(1) and M(3) sites, as well as with the Fe3+-Al3+ replacement in the M(4) site. However, the mean observed M(2)-O distance is considerably shorter than prescribed, due to a slight increase of the Fe3+ content in the M(2) site. Such replacement was compensated by slight increase of the Fe2+ content in the M(4) site, resulting in the (Mg1.48Fe2+0.46Fe3+0.05Mn0.02)2.01(Fe3+0.94Fe2+0.04Al0.02)1.00B1.00O5 composition. The formation temperature was estimated to be about 500-600°C. The influences of the various chemical compositions to the crystallographic parameters, M-O distances, M(3) and M(4) sites shift, distortion parameters and estimated valences, were also studied and compared with other reference samples. | Pavle TANCIC Radovan DIMITRIJEVIC Maja POZNANOVIC Aleksandar PACEVSKI Slobodanka SUDAR | 2012 | Acta Geologica Sinica(English Edition)2012，86，6： | 1 |
| 2 | FTIR Spectroscopy of Framework Aluminosilicate Structures:Carnegieite and Pure Sodium Nepheline显示文摘 | Smilja Markovic Vera Dondur Radovan Dimitrijevic | 2003 | Journal of Molecular Structure2003，654，： | 1 |
| 3 | Macroscopically-Zoned Grandite from the Garnetite Skarn of Meka Presedla(Kopaonik Mountain,Serbia)显示文摘The macroscopically-zoned grandite from the garnetite skarn of Meka Presedla(Kopaonik Mountain,Serbia) was studied with optical microscopy,electron microprobe analysis(EMPA),Fourier transform infra-red(FT-IR),and Raman methods.The EMPA results indicate that the main core-rim compositional variations(Ca2.93-2.97Mn0.05-0.06Mg0.00-0.01Al1.14-1.26Fe3+0.72-0.83Ti0.00-0.02Si2.97-3.02O12) slightly differ along the zones,showing evidence for a quasi-cyclic alternation of the oscillatory zoning nature.Among this,considerable variation is observed only by the Al-Fe3+ substitutions in the octahedral site.The EMPA also indicate that the grandite zones compositionally vary,mostly within ±1 and ±2 mol% of the homogeneity level range,that is,Grs64±1Adr36±1Sps2(A),Grs62±1Adr38±1Sps2(B),Grs59±2Adr40±2Sps2(C),Grs58±2Adr41±2Sps2(D),and Grs58±1Adr41±1Sps2(E).Therefore,the investigated garnet can be considered as relatively highly homogeneous.The majority of compositions lie within the narrow miscibility region of 0.58±2 | Pavle TANCIC Predrag VULIC Reinhard KAINDL Bernhard SARTORY Radovan DIMITRIJEVIC | 2012 | Acta Geologica Sinica(English Edition)2012，86，2： | 1 |
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