Synthesis and properties of NaFeGe2O6 polycrystals

Anisotropy study of multiferroicity in the pyroxene NaFeGe2O6

“…Measurements of the magnetic susceptibility revealed the occurrence of low-dimensional magnetic correlations around 35 K, succeeded by the onset of a three-dimensional antiferromagnetic order below ≃13 K [20,26,27]. Previous results of magnetic susceptibility and Mössbauer spectroscopy measurements had indicated a slightly higher Néel temperature of about 15 K [28,29]. Among the group of Fe 3+ -based pyroxenes, NaFeGe 2 O 6 exhibits the most pronounced low-dimensional magnetic characteristics [20].…”

“…The vast majority of the investigations of NaFeGe 2 O 6 were performed on polycrystalline powder samples [20,[26][27][28][29]. Measurements of the magnetic susceptibility revealed the occurrence of low-dimensional magnetic correlations around 35 K, succeeded by the onset of a three-dimensional antiferromagnetic order below ≃13 K [20,26,27].…”

Investigation of the magnetic structure in NaFeGe2O6using neutron powder diffraction

“…The two types of ribbons alternate along the b axis. The structure of the magnetic subsystem in pyroxenes is quasi-one-dimensional [3,4]. The theoretical and experimental peculiarities of low-dimensional insulating systems with a low magnetic transition temperature were discussed that emphasized the importance of the investigation of the magnetic ordering in such systems [3].…”

Low Temperature Synthesis of Aegirine NaFeSi2O6: Spectroscopy (57Fe Mössbauer, Raman) and Size/Strain Analysis from X-ray Powder Diffraction

“…Finally, Raman spectroscopy showed that some weakly-developed pre-ordering effects were present in the samples, which appeared to be amorphous in PXRD, while well-resolved spectra appeared as soon as the long-range ordered crystalline state could be found with X-ray diffraction.CaFeSi 2 O 6 -aegirine series [4][5][6], diopside CaMgSi 2 O 6 -aegirine series [7][8][9]; the thermal and high pressure behavior [10,11] and the implications of the presence of the aegirine molecule for the behaviour of naturally occurring augitic pyroxenes.In recent years, aegirine has also attracted the attention of numerous physicists due to the observation of multiferroic properties [12], resulting in several studies on its low temperature magnetic properties. In addition, the phase relations and magnetic properties within the (Na,Li)Fe(Si,Ge) 2 O 6 system were investigated with special interest [13][14][15][16][17][18][19][20][21][22][23][24][25]. Aegirine itself shows complex magnetic ordering at low temperatures and discrepancies have been found in the magnetic ground states of naturally-occurring single crystals (with diopsidic and hedenbergitic component dilutions) and synthetic end-member compositions.It was already noted by Ballet and co-workers [26] that phase-pure synthetic NaFeSi 2 O 6 charges are hard to obtain, and that material, produced in ceramic sintering experiments at high temperatures around 900 • C, always contains up to 3-10 wt.…”

“…In recent years, aegirine has also attracted the attention of numerous physicists due to the observation of multiferroic properties [12], resulting in several studies on its low temperature magnetic properties. In addition, the phase relations and magnetic properties within the (Na,Li)Fe(Si,Ge) 2 O 6 system were investigated with special interest [13][14][15][16][17][18][19][20][21][22][23][24][25]. Aegirine itself shows complex magnetic ordering at low temperatures and discrepancies have been found in the magnetic ground states of naturally-occurring single crystals (with diopsidic and hedenbergitic component dilutions) and synthetic end-member compositions.…”