najoNanosystems: Physics, Chemistry, MathematicsНаносистемы: физика, химия, математика2220-80542305-7971Университет ИТМО10.17586/2220-8054-2024-15-6-821-836najo-179Research ArticleCHEMISTRY AND MATERIALS SCIENCEХИМИЯ И НАУКА О МАТЕРИАЛАХIntermetallic compounds obtained from Me3Ge2O5(OH)4 (Me = Mg, Ni, Fe, Co) phyllogermanates: synthesis of single-phase precursorsИнтерметаллиды, полученные из гидрогерманатов Me3Ge2O5(OH)4 (Me = Mg, Ni, Fe, Co): синтез однофазных прекурсоровhttps://orcid.org/0000-0003-2674-9653ХраповаЕ. К.KhrapovaE. K.

Ekaterina K. Khrapova

194021 St. Petersburg

e.k.khrapova@mail.ioffe.ruhttps://orcid.org/0000-0002-8134-1506ИвановаА. А.IvanovaA. A.

Anastasia A. Ivanova

194021 St. Petersburg

a.a.ivanova@mail.ioffe.ruhttps://orcid.org/0000-0002-1571-209XКириленкоД. А.KirilenkoD. A.

Demid A. Kirilenko

194021 St. Petersburg

demid.kirilenko@mail.ioffe.ruhttps://orcid.org/0000-0002-3938-3024КрасилинА. А.KrasilinA. A.

Andrei A. Krasilin

194021 St. Petersburg

ikrasilin@mail.ioffe.ruIoffe InstituteRussian Federation202405062025156821836Copyright © Khrapova E.K., Ivanova A.A., Kirilenko D.A., Krasilin A.A., 20252025Храпова Е.К., Иванова А.А., Кириленко Д.А., Красилин А.А.Khrapova E.K., Ivanova A.A., Kirilenko D.A., Krasilin A.A.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://nanojournal.ifmo.ru/jour/article/view/179

Typically, intermetallic compounds are prepared by solid-state method at high temperatures. We propose a simple method to obtain intermetallic compounds by reduction in Ar–H2 atmosphere from precursors. In particular, Co2+ and Fe2+ oxidation in hydrothermal conditions grants additional experimental challenge. Here, we report successful Fe phyllogermanate synthesis for the first time. We identify general patterns of formation and determine the effect of hydrothermal treatment on phase composition and morphology for the whole series of phyllogermanates. Formation of phyllogermanates under hydrothermal conditions is studied in the 100 – 200◦C temperature range in three hydrothermal media: H2O, NaOH, Na2SO3. The latter inhibits the oxidation of Co2+ and Fe2+ during the synthesis. An increase in temperature favors to the formation of phase described by three-layers unit cell. Heat treatment in an Ar–H2 atmosphere allows us to obtain intermetallic compounds and MexGey alloys, and to establish the temperature regimes of the reduction processes.

Обычно интерметаллиды получают твердофазным методом при высоких температурах. В данной работе предложен простой метод получения интерметаллидов путем восстановления из прекурсоров в атмосфере Ar-H2. Окисление Co2+ и Fe2+ в гидротермальных условиях представляет собой дополнительную экспериментальную задачу. В данной работе мы впервые сообщаем об успешном синтезе Fe-гидрогерманата. Выявлены общие закономерности образования гидрогерманатов и определено влияние гидротермальной обработки на фазовый состав и морфологию для всего ряда гидрогерманатов. Образование гидрогерманатов в гидротермальных условиях изучалось в диапазоне температур 100-200 ℃ в трех гидротермальных средах: H2O, NaOH, Na2SO3. Последняя ингибировала окисление Co2+ и Fe2+ во время синтеза. Повышение температуры способствовало образованию фазы, описываемой трехслойной элементарной ячейкой. Термическая обработка в атмосфере Ar-H2 позволила получить интерметаллиды и сплавы MexGey, а также установить температурные режимы восстановительных процессов.

интерметаллидыгидрогерманатгидротермальный синтезвосстановлениеintermetallic compoundsphyllogermanatehydrothermal synthesisreductionThe work was financially supported by the Russian Science Foundation (Project No. 23-22-00245, https://rscf.ru/project/23-22-00245/). Powder X-ray diffraction was performed using the equipment of the Engineering Centre of St. Petersburg State Technical University (Technical Institute). TEM studies were performed using equipment of the Federal Joint Research Center “Material science and characterization in advanced technology” supported by the Ministry of Science and Higher Education of the Russian Federation.ReferencesRoveri N., Falini G., Foresti E., Fracasso G., Lesci I.G., Sabatino P. Geoinspired synthetic chrysotile nanotubes. J. of materials research, 2006, 21 (11), P. 2711–2725.Roveri N., Falini G., Foresti E., Fracasso G., Lesci I.G., Sabatino P. Geoinspired synthetic chrysotile nanotubes. J. of materials research, 2006, 21 (11), P. 2711–2725.Korytkova E.N., Maslov A.V., Pivovarova L.N., Drozdova I.A., Gusarov V.V. Formation of Mg3Si2O5(OH)4 nanotubes under hydrothermal conditions. Glass Physics and Chemistry, 2004, 30, P. 51–55.Korytkova E.N., Maslov A.V., Pivovarova L.N., Drozdova I.A., Gusarov V.V. Formation of Mg3Si2O5(OH)4 nanotubes under hydrothermal conditions. Glass Physics and Chemistry, 2004, 30, P. 51–55.Mellini M. The crystal structure of lizardite 1 T: hydrogen bonds and polytypism. American Mineralogist, 1982, 67 (5–6), P. 587–598.Mellini M. The crystal structure of lizardite 1 T: hydrogen bonds and polytypism. American Mineralogist, 1982, 67 (5–6), P. 587–598.Alvarez-Ram´ırez F., Toledo-Antonio J.A., Angeles-Chavez C., Guerrero-Abreo J.H., L´opez-Salinas E. Complete structural characterization of Ni3Si2O5(OH)4 nanotubes: theoretical and experimental comparison. The J. of Physical Chemistry C, 2011, 115 (23), P. 11442–11446.Alvarez-Ram´ırez F., Toledo-Antonio J.A., Angeles-Chavez C., Guerrero-Abreo J.H., L´opez-Salinas E. Complete structural characterization of Ni3Si2O5(OH)4 nanotubes: theoretical and experimental comparison. The J. of Physical Chemistry C, 2011, 115 (23), P. 11442–11446.Krasilin A.A., Semenova A.S., Kellerman D.G., Nevedomsky V.N., Gusarov V.V. Magnetic properties of synthetic Ni3Si2O5(OH)4 nanotubes. Europhysics Letters, 2016, 113 (4), 47006.Krasilin A.A., Semenova A.S., Kellerman D.G., Nevedomsky V.N., Gusarov V.V. Magnetic properties of synthetic Ni3Si2O5(OH)4 nanotubes. Europhysics Letters, 2016, 113 (4), 47006.Korytkova E.N., Maslov A.V., Pivovarova L.N., Polegotchenkova Y.V., Povinich V.F., Gusarov V.V. Synthesis of nanotubular Mg3Si2O5(OH)4– Ni3Si2O5(OH)4 silicates at elevated temperatures and pressures. Inorganic materials, 2005, 41, P. 743–749.Korytkova E.N., Maslov A.V., Pivovarova L.N., Polegotchenkova Y.V., Povinich V.F., Gusarov V.V. Synthesis of nanotubular Mg3Si2O5(OH)4– Ni3Si2O5(OH)4 silicates at elevated temperatures and pressures. Inorganic materials, 2005, 41, P. 743–749.Korytkova E.N., Pivovarova L.N. Hydrothermal synthesis of nanotubes based on (Mg, Fe, Co, Ni)3Si2O5(OH)4 hydrosilicates. Glass Physics and Chemistry, 2010, 36, P. 53–60.Korytkova E.N., Pivovarova L.N. Hydrothermal synthesis of nanotubes based on (Mg, Fe, Co, Ni)3Si2O5(OH)4 hydrosilicates. Glass Physics and Chemistry, 2010, 36, P. 53–60.Khrapova E.K., Ivanova A.A., Kirilenko D.A., Levin A.A., Bert N.A., Ugolkov V.L., Krasilin A.A. Phase transformations of (CoxMg1−x)3Si2O5(OH)4 phyllosilicate nanoscrolls upon heating in Ar, O2 and H2 containing atmospheres. Applied Clay Science, 2024, 250, 107282.Khrapova E.K., Ivanova A.A., Kirilenko D.A., Levin A.A., Bert N.A., Ugolkov V.L., Krasilin A.A. Phase transformations of (CoxMg1−x)3Si2O5(OH)4 phyllosilicate nanoscrolls upon heating in Ar, O2 and H2 containing atmospheres. Applied Clay Science, 2024, 250, 107282.Khrapova E.K., Kozlov D.A., Krasilin A.A. Hydrothermal Synthesis of Hydrosilicate Nanoscrolls (Mg1−xCox)3Si2O5(OH)4 in a Na2SO3 Solution. Russian J. of Inorganic Chemistry, 2022, 67 (6), P. 839–849.Khrapova E.K., Kozlov D.A., Krasilin A.A. Hydrothermal Synthesis of Hydrosilicate Nanoscrolls (Mg1−xCox)3Si2O5(OH)4 in a Na2SO3 Solution. Russian J. of Inorganic Chemistry, 2022, 67 (6), P. 839–849.Korytkova E.N., Pivovarova L.N., Gusarov V.V. Influence of iron on the kinetics of formation of chrysotile nanotubes of composition (Mg, Fe)3Si2O5(OH)4 under hydrothermal conditions. Geochemistry International, 2007, 45, P. 825–831.Korytkova E.N., Pivovarova L.N., Gusarov V.V. Influence of iron on the kinetics of formation of chrysotile nanotubes of composition (Mg, Fe)3Si2O5(OH)4 under hydrothermal conditions. Geochemistry International, 2007, 45, P. 825–831.Krasilin A.A., Panchuk V.V., Semenov V.G., Gusarov V.V. Formation of variable-composition iron (III) hydrosilicates with the chrysotile structure. Russian J. of General Chemistry, 2016, 86, P. 2581–2588.Krasilin A.A., Panchuk V.V., Semenov V.G., Gusarov V.V. Formation of variable-composition iron (III) hydrosilicates with the chrysotile structure. Russian J. of General Chemistry, 2016, 86, P. 2581–2588.Foresti E., Hochella Jr M.F., Kornishi H., Lesci I.G., Madden A.S., Roveri N., Xu H. Morphological and Chemical/Physical Characterization of Fe-Doped Synthetic Chrysotile Nanotubes. Advanced Functional Materials, 2005, 15 (6), P. 1009–1016.Foresti E., Hochella Jr M.F., Kornishi H., Lesci I.G., Madden A.S., Roveri N., Xu H. Morphological and Chemical/Physical Characterization of Fe-Doped Synthetic Chrysotile Nanotubes. Advanced Functional Materials, 2005, 15 (6), P. 1009–1016.Bloise A., Barrese E., Apollaro C. Hydrothermal alteration of Ti-doped forsterite to chrysotile and characterization of the resulting chrysotile fibers. Neues Jahrbuch f¨ur Mineralogie, 2009, 185 (3), P. 297–304.Bloise A., Barrese E., Apollaro C. Hydrothermal alteration of Ti-doped forsterite to chrysotile and characterization of the resulting chrysotile fibers. Neues Jahrbuch f¨ur Mineralogie, 2009, 185 (3), P. 297–304.Roy D.M., Roy R. An experimental study of the formation and properties of synthetic serpentines and related layer silicate minerals. American Mineralogist: J. of Earth and Planetary Materials, 1954, 39 (11–12), P. 957–975.Roy D.M., Roy R. An experimental study of the formation and properties of synthetic serpentines and related layer silicate minerals. American Mineralogist: J. of Earth and Planetary Materials, 1954, 39 (11–12), P. 957–975.Krasilin A.A., Khrapova E. K. Effect of hydrothermal treatment conditions on formation of nickel hydrogermanate with platy morphology. Russian J. of Applied Chemistry, 2017, 90, P. 22–27.Krasilin A.A., Khrapova E. K. Effect of hydrothermal treatment conditions on formation of nickel hydrogermanate with platy morphology. Russian J. of Applied Chemistry, 2017, 90, P. 22–27.White R.D., Bavykin D.V., Walsh F.C. Spontaneous scrolling of kaolinite nanosheets into halloysite nanotubes in an aqueous suspension in the presence of GeO2. The J. of Physical Chemistry C, 2012, 116 (15), P. 8824–8833.White R.D., Bavykin D.V., Walsh F.C. Spontaneous scrolling of kaolinite nanosheets into halloysite nanotubes in an aqueous suspension in the presence of GeO2. The J. of Physical Chemistry C, 2012, 116 (15), P. 8824–8833.Paineau E. Imogolite nanotubes: a flexible nanoplatform with multipurpose applications. Applied Sciences, 2018, 8 (10), 1921.Paineau E. Imogolite nanotubes: a flexible nanoplatform with multipurpose applications. Applied Sciences, 2018, 8 (10), 1921.Hall S.H., Guggenheim S., Moore P., Bailey S.W. The structure of Unst-type 6-layer serpentines. The Canadian Mineralogist, 1976, 14 (3), P. 314–321.Hall S.H., Guggenheim S., Moore P., Bailey S.W. The structure of Unst-type 6-layer serpentines. The Canadian Mineralogist, 1976, 14 (3), P. 314–321.Belskaya N.A., Khrapova E.K., Ivanova A.A., Eremin E.V., Pavlov S.I., Krasilin A.A. Structure refinement and magnetic properties of synthetic Co3Ge2O5(OH)4 phyllogermanate. J. of Magnetism and Magnetic Materials, 2023, 587, 171262.Belskaya N.A., Khrapova E.K., Ivanova A.A., Eremin E.V., Pavlov S.I., Krasilin A.A. Structure refinement and magnetic properties of synthetic Co3Ge2O5(OH)4 phyllogermanate. J. of Magnetism and Magnetic Materials, 2023, 587, 171262.Abdelkrim Y., Wu J., Jiao F.Z., Wang Z.H., Hou S.X., Zhang T.T., Qu J. Cobalt germanium hydroxides with asymmetric electron distribution and surface hydroxyl groups for superb catalytic degradation performances. J. of Colloid and Interface Science, 2025, 677, P. 282–293.Abdelkrim Y., Wu J., Jiao F.Z., Wang Z.H., Hou S.X., Zhang T.T., Qu J. Cobalt germanium hydroxides with asymmetric electron distribution and surface hydroxyl groups for superb catalytic degradation performances. J. of Colloid and Interface Science, 2025, 677, P. 282–293.Xu Z., Li W., Wang X., Wang B., Shi Z., Dong C., Zou Z. Novel cobalt germanium hydroxide for electrochemical water oxidation. ACS applied materials & interfaces, 2018, 10 (36), P. 30357–30366.Xu Z., Li W., Wang X., Wang B., Shi Z., Dong C., Zou Z. Novel cobalt germanium hydroxide for electrochemical water oxidation. ACS applied materials & interfaces, 2018, 10 (36), P. 30357–30366.Zhang N., Yang B., He Y., He Y., Liu X., Liu M., Roy V.A. Serpentine Ni3Ge2O5(OH)4 nanosheets with tailored layers and size for efficient oxygen evolution reactions. Small, 2018, 14 (48), 1803015.Zhang N., Yang B., He Y., He Y., Liu X., Liu M., Roy V.A. Serpentine Ni3Ge2O5(OH)4 nanosheets with tailored layers and size for efficient oxygen evolution reactions. Small, 2018, 14 (48), 1803015.Yang B., Zhang N., Chen G., Liu K., Yang J., Pan A., Qiu T. Serpentine CoxNi3−xGe2O5(OH)4 nanosheets with tuned electronic energy bands for highly efficient oxygen evolution reaction in alkaline and neutral electrolytes. Applied Catalysis B: Environmental, 2020, 260, 118184.Yang B., Zhang N., Chen G., Liu K., Yang J., Pan A., Qiu T. Serpentine CoxNi3−xGe2O5(OH)4 nanosheets with tuned electronic energy bands for highly efficient oxygen evolution reaction in alkaline and neutral electrolytes. Applied Catalysis B: Environmental, 2020, 260, 118184.Wen N., Chen S., Feng J., Zhang K., Zhou Z., Li X., Zhao Y. In situ hydrothermal synthesis of double-carbon enhanced novel cobalt germanium hydroxide composites as promising anode material for sodium ion batteries. Dalton transactions, 2021, 50 (12), P. 4288–4299.Wen N., Chen S., Feng J., Zhang K., Zhou Z., Li X., Zhao Y. In situ hydrothermal synthesis of double-carbon enhanced novel cobalt germanium hydroxide composites as promising anode material for sodium ion batteries. Dalton transactions, 2021, 50 (12), P. 4288–4299.Li H.S., Qu J., Hao S.M., Wang Z.Z., Zhang Y.J., Yu Z.Z. Enhanced lithium storage performances of novel layered nickel germanate anodes inspired by the spatial arrangement of lotus leaves. Nanoscale, 2018, 10 (23), P. 10963–10970.Li H.S., Qu J., Hao S.M., Wang Z.Z., Zhang Y.J., Yu Z.Z. Enhanced lithium storage performances of novel layered nickel germanate anodes inspired by the spatial arrangement of lotus leaves. Nanoscale, 2018, 10 (23), P. 10963–10970.Liu F., Ye S., Guo H., Zhai M., Qian J. Assembled β-Co(OH)2 Nanoparticles on Reduced Graphene Oxide for Enhanced Magnetism. J. of Superconductivity and Novel Magnetism, 2014, 27, P. 787–791.Liu F., Ye S., Guo H., Zhai M., Qian J. Assembled β-Co(OH)2 Nanoparticles on Reduced Graphene Oxide for Enhanced Magnetism. J. of Superconductivity and Novel Magnetism, 2014, 27, P. 787–791.Gaudet S., Detavernier C., Kellock A.J., Desjardins P., Lavoie C. Thin film reaction of transition metals with germanium. J. of Vacuum Science & Technology A, 2006, 24 (3), P. 474–485.Gaudet S., Detavernier C., Kellock A.J., Desjardins P., Lavoie C. Thin film reaction of transition metals with germanium. J. of Vacuum Science & Technology A, 2006, 24 (3), P. 474–485.Sadoh T., Kamizuru H., Kenjo A., Miyao M. Low-temperature formation (< 500 ◦ C) of poly-Ge thin-film transistor with NiGe Schottky source/drain. Applied physics letters, 2006, 89 (19).Sadoh T., Kamizuru H., Kenjo A., Miyao M. Low-temperature formation (< 500 ◦ C) of poly-Ge thin-film transistor with NiGe Schottky source/drain. Applied physics letters, 2006, 89 (19).Kauzlarich S.M., Ju Z., Tseng E., Lundervold J. Recent developments in germanium containing clusters in intermetallics and nanocrystals. Chemical Society Reviews, 2021, 50 (23), P. 13236–13252.Kauzlarich S.M., Ju Z., Tseng E., Lundervold J. Recent developments in germanium containing clusters in intermetallics and nanocrystals. Chemical Society Reviews, 2021, 50 (23), P. 13236–13252.Menezes P.W., Yao S., Beltr´an?Suito R., Hausmann J.N., Menezes P.V., Driess M. Facile access to an active γ-NiOOH electrocatalyst for durable water oxidation derived from an intermetallic nickel germanide precursor. Angewandte Chemie, 2021, 133 (9), P. 4690–4697.Menezes P.W., Yao S., Beltr´an?Suito R., Hausmann J.N., Menezes P.V., Driess M. Facile access to an active γ-NiOOH electrocatalyst for durable water oxidation derived from an intermetallic nickel germanide precursor. Angewandte Chemie, 2021, 133 (9), P. 4690–4697.Walter C., Menezes P. W., Driess M. Perspective on intermetallics towards efficient electrocatalytic water-splitting. Chemical Science, 2021, 12 (25), P. 8603–8631.Walter C., Menezes P. W., Driess M. Perspective on intermetallics towards efficient electrocatalytic water-splitting. Chemical Science, 2021, 12 (25), P. 8603–8631.Toraya H. Quantitative phase analysis using observed integrated intensities and chemical composition data of individual crystalline phases: quantification of materials with indefinite chemical compositions. J. of Applied Crystallography, 2017, 50 (3), P. 820–829.Toraya H. Quantitative phase analysis using observed integrated intensities and chemical composition data of individual crystalline phases: quantification of materials with indefinite chemical compositions. J. of Applied Crystallography, 2017, 50 (3), P. 820–829.Toraya H. Whole-powder-pattern fitting without reference to a structural model: application to X-ray powder diffraction data. J. of Applied Crystallography, 1986, 19 (6), P. 440–447.Toraya H. Whole-powder-pattern fitting without reference to a structural model: application to X-ray powder diffraction data. J. of Applied Crystallography, 1986, 19 (6), P. 440–447.Schneider C.A., Rasband W.S., Eliceiri K.W. NIH Image to ImageJ: 25 years of image analysis. Nature methods, 2012, 9 (7), P. 671–675.Schneider C.A., Rasband W.S., Eliceiri K.W. NIH Image to ImageJ: 25 years of image analysis. Nature methods, 2012, 9 (7), P. 671–675.Ivanov V.K., Fedorov P.P., Baranchikov A.Y., Osiko V.V.E. Oriented attachment of particles: 100 years of investigations of non-classical crystal growth. Russian Chemical Reviews, 2014, 83 (12), 1204.Ivanov V.K., Fedorov P.P., Baranchikov A.Y., Osiko V.V.E. Oriented attachment of particles: 100 years of investigations of non-classical crystal growth. Russian Chemical Reviews, 2014, 83 (12), 1204.Pokrovski G.S., Schott J. Thermodynamic properties of aqueous Ge (IV) hydroxide complexes from 25 to 350 C: implications for the behavior of germanium and the Ge/Si ratio in hydrothermal fluids. Geochimica et Cosmochimica Acta, 1998, 62 (9), P. 1631–1642.Pokrovski G.S., Schott J. Thermodynamic properties of aqueous Ge (IV) hydroxide complexes from 25 to 350 C: implications for the behavior of germanium and the Ge/Si ratio in hydrothermal fluids. Geochimica et Cosmochimica Acta, 1998, 62 (9), P. 1631–1642.Lin J.X., Wang L. Adsorption of dyes using magnesium hydroxide-modified diatomite. Desalination and Water Treatment, 2009, 8 (1–3), P. 263– 271.Lin J.X., Wang L. Adsorption of dyes using magnesium hydroxide-modified diatomite. Desalination and Water Treatment, 2009, 8 (1–3), P. 263– 271.Hern´andez N., Moreno R., S´anchez-Herencia A.J., Fierro J.L. Surface behavior of nickel powders in aqueous suspensions. The J. of Physical Chemistry B, 2005, 109 (10), P. 4470–4474.Hern´andez N., Moreno R., S´anchez-Herencia A.J., Fierro J.L. Surface behavior of nickel powders in aqueous suspensions. The J. of Physical Chemistry B, 2005, 109 (10), P. 4470–4474.Lorenzen A.L., Rossi T.S., Riegel-Vidotti I.C., Vidotti M. Influence of cationic and anionic micelles in the (sono) chemical synthesis of stable Ni(OH)2 nanoparticles: “In situ” zeta-potential measurements and electrochemical properties. Applied Surface Science, 2018, 455, P. 357–366.Lorenzen A.L., Rossi T.S., Riegel-Vidotti I.C., Vidotti M. Influence of cationic and anionic micelles in the (sono) chemical synthesis of stable Ni(OH)2 nanoparticles: “In situ” zeta-potential measurements and electrochemical properties. Applied Surface Science, 2018, 455, P. 357–366.White R.D., Bavykin D.V., Walsh F.C. Morphological control of synthetic Ni3Si2O5(OH)4 nanotubes in an alkaline hydrothermal environment. J. of Materials Chemistry A, 2013, 1 (3), P. 548–556.White R.D., Bavykin D.V., Walsh F.C. Morphological control of synthetic Ni3Si2O5(OH)4 nanotubes in an alkaline hydrothermal environment. J. of Materials Chemistry A, 2013, 1 (3), P. 548–556.Krasilin A.A., Nevedomsky V.N., Gusarov V.V. Comparative energy modeling of multiwalled Mg3Si2O5(OH)4 and Ni3Si2O5(OH)4 nanoscroll growth. The J. of Physical Chemistry C, 121 (22), P. 12495–12502.Krasilin A.A., Nevedomsky V.N., Gusarov V.V. Comparative energy modeling of multiwalled Mg3Si2O5(OH)4 and Ni3Si2O5(OH)4 nanoscroll growth. The J. of Physical Chemistry C, 121 (22), P. 12495–12502.Bloise A., Belluso E., Barrese E., Miriello D., Apollaro C. Synthesis of Fe-doped chrysotile and characterization of the resulting chrysotile fibers. Crystal Research and Technology: J. of Experimental and Industrial Crystallography. 44 (6), P. 590–596.Bloise A., Belluso E., Barrese E., Miriello D., Apollaro C. Synthesis of Fe-doped chrysotile and characterization of the resulting chrysotile fibers. Crystal Research and Technology: J. of Experimental and Industrial Crystallography. 44 (6), P. 590–596.Dzene L., Brendle J., Limousy L., Dutournie P., Martin C., Michau N. Synthesis of iron-rich tri-octahedral clay minerals: A review. Applied Clay Science, 2018, 166, P. 276–287.Dzene L., Brendle J., Limousy L., Dutournie P., Martin C., Michau N. Synthesis of iron-rich tri-octahedral clay minerals: A review. Applied Clay Science, 2018, 166, P. 276–287.Pignatelli I., Mosser-Ruck R., Mugnaioli E., Sterpenich J., Gemmi M. The effect of the starting mineralogical mixture on the nature of Feserpentines obtained during hydrothermal synthesis at 90 C. Clays and Clay Minerals, 2020, 68 (4), P. 394–412.Pignatelli I., Mosser-Ruck R., Mugnaioli E., Sterpenich J., Gemmi M. The effect of the starting mineralogical mixture on the nature of Feserpentines obtained during hydrothermal synthesis at 90 C. Clays and Clay Minerals, 2020, 68 (4), P. 394–412.Zieli˜nski J., Zglinicka I., Znak L., Kaszkur Z. Reduction of Fe2O3 with hydrogen. Applied Catalysis A: General, 2010, 381 (1–2), P. 191–196.Zieli˜nski J., Zglinicka I., Znak L., Kaszkur Z. Reduction of Fe2O3 with hydrogen. Applied Catalysis A: General, 2010, 381 (1–2), P. 191–196.Bielz T., Soisuwan S., Girgsdies F., Klo?tzer B., Penner S. Reduction of different GeO2 polymorphs. The J. of Physical Chemistry C, 2012, 116 (18), P. 9961–9968.Bielz T., Soisuwan S., Girgsdies F., Klo?tzer B., Penner S. Reduction of different GeO2 polymorphs. The J. of Physical Chemistry C, 2012, 116 (18), P. 9961–9968.Chen C.X., Wu S.P., Fan Y.X. Synthesis and microwave dielectric properties of B2O3-doped Mg2GeO4 ceramics. J. of alloys and compounds, 2013, 578, P. 153–156.Chen C.X., Wu S.P., Fan Y.X. Synthesis and microwave dielectric properties of B2O3-doped Mg2GeO4 ceramics. J. of alloys and compounds, 2013, 578, P. 153–156.Yamaguchi O., Matumoto H., Morikawa S., Shimizu K. Preparation and Thermal Behavior of Magnesium?Germanium Hydroxide. J. of the American Ceramic Society, 1983, 66 (9), P. c169–c170.Yamaguchi O., Matumoto H., Morikawa S., Shimizu K. Preparation and Thermal Behavior of Magnesium?Germanium Hydroxide. J. of the American Ceramic Society, 1983, 66 (9), P. c169–c170.Liu Y.Q., Ma D.J., Du Y. Thermodynamic modeling of the germanium–nickel system. J. of Alloys and Compounds, 2010, 491 (1–2), P. 63–71.Liu Y.Q., Ma D.J., Du Y. Thermodynamic modeling of the germanium–nickel system. J. of Alloys and Compounds, 2010, 491 (1–2), P. 63–71.Okamoto H. Fe–Ge (iron-germanium). J. of Phase Equilibria and Diffusion, 2008, 29 (3), 292.Okamoto H. Fe–Ge (iron-germanium). J. of Phase Equilibria and Diffusion, 2008, 29 (3), 292.Audebrand N., Ellner M., Mittemeijer E J. High-temperature ordering of structural vacancies in the cobalt-rich portion of the binary system Co–Ge. J. of alloys and compounds, 2005, 388 (2), P. 230–234.Audebrand N., Ellner M., Mittemeijer E J. High-temperature ordering of structural vacancies in the cobalt-rich portion of the binary system Co–Ge. J. of alloys and compounds, 2005, 388 (2), P. 230–234.

The authors declare that there are no conflicts of interest present.