About

Visiting Research Fellow in Mineral Chemistry.

I retired from the University as a full-time staff member in Geosciences, Department of Natural Sciences. However, I am continuing with research in collaboration with Professor Hugh Rollinson and am also teaching as an Associate Lecturer.

Teaching responsibilities

I teach in the IOA General Acoustics module and I'm part of the team running the Laboratory for the Diploma in Acoustics.

I also teach some of the IOA Short Courses in Environmental Noise Measurement and Workplace Noise Assessment.

I am part of the team supervising the first-year laboratory module on Rocks, Minerals and Gemstones.

Before retiring, I was the leader in two modules for the On-Campus MSc Environmental Management Program: modules on Air Pollution and Radiation Pollution aspects of Environmental Physics and Chemistry. Among others, I also taught in the undergraduate Geophysics module.

Research interests

Over the years, my research activities have spanned TEM studies of Ar-ion channelling and sputtering behaviour of single crystal carbonates, as well as pseudo-potential defect centre calculations in alkali-halides. Later my attention was focused on the use of the Fe-Mössbauer technique in the characterisation of iron-bearing natural and synthetic minerals. Fortunately, Fe, which is a typical Mössbauer element, is one of the major constituents of the earth’s crust (5%) and is commonly found in rocks, soils and sediments. Iron exists in various oxidation states which can be characterised by the Mössbauer spectroscopic technique, and its 14.4keV gamma radiation source can serve as a probe for monitoring chemical changes occurring in the atomic environment, elucidating their mechanisms.

In recent years, my research has focused on the use of the Mössbauer technique for characterising geological materials, with particular interest in chromite from mantle sections of ophiolites. Chromite is the only mineral in basalts that contains both Fe²⁺ and Fe³⁺ ions and, therefore, their ratios can be a geo-thermometry to study the oxygen environment that existed in the magma, helping to establish whether the origin or evolution of the magma is associated with different oxygen fugacities.

Membership of professional bodies

• Fellow of the Nigerian Institute of Physics
• Member of the Editorial Board African Journal of Science & Technology (1998-present)
• Member of the Mössbauer Group of the Royal Society of Chemistry (1994-2004)

Qualifications

• BSc (Physics-Major and Pure Mathematics) University of Ghana, Legon, Accra
• MSc (Opto-electronics) University of Essex
• PhD (Materials Physics) University of Essex
• The Institute of Acoustics (London) Certificate in Environmental Noise Measurement

Recent conferences

• International Conference on the Applications of Mössbauer Effect, 1999, 2001, 2003
• The 28th Society for Environmental Geochemistry & Health SEGH) incorporating the  European Conference and Workshops,  April 2011, Edge Hill, Ormskirk, UK
• International Conference on the Geology of the Arabian Plate and the Oman Mountains, 7-9^th January 2012, Sultan Qaboos University, Muscat, Sultanate of Oman

International experience

• Post-doctoral Research Fellow at the International Centre for Theoretical Physics 1978-79. Trieste, Italy
• Visiting Research Fellow, Department of Mineralogy and Petrology, University of Uppsala, Sweden, (1983-84). I carried out Mössbauer spectroscopic studies of cation ordering in Fe-Mn synthetic and natural silicate olivines
• Visiting Research Professor, Department of Physics, University of Sheffield (1993-2004). Among others, my work included Mössbauer spectroscopic determination of magnetic moments of Fe³⁺-and Co²⁺ ion- substituted barium hexaferrite,  Ba(Co,Ti)_xFe_(12-2x)O₁₉
• Professor and Head of the Department of Physics, (1986-1993), Ahmadu Bello University, Zaria, Nigeria

In the media

I wrote an article entitled, ‘Explainer: what dust from the Sahara does to you and the planet', for an online journal, The ConversationTrust, issue 21 April 2016. The article can be accessed at: http://theconversation.com/explainer-what-dust-from- the-sahara- does-to-you-and-the-planet-57373

The ConversationTrust journal is funded by seventy UK Universities, the Wellcome Trust, The Royal Society, the Press Association, the Research Council, the Nuffield Foundation, etc.

Recent publications

• Hugh Rollinson and Jacob Adetunji (Oct 2023). Ferric iron in chrome-bearing spinels: implications for microprobe correction procedures. Mineralogical Magazine, Volume 87, Issue 5, October 2023, pp. 702-710. DOI: https://doi.org/10.1180/mgm.2023.68 
• John Stubbs and Jacob Adetunji (July 2023). The repayment of financial debt: some mathematical considerations. Mathematical Gazette. Vol. 107 Number 569 pp. 204-217. DOI: https://doi.org/10.1017/mag.2023.51 
• Lenaze, D; Maibam, B; Adetunji, J; Skogby, H. (Dec 2021) The Effects of High-Grade Metamorphism on Cr-Spinel from the Achean Sittampundi Complex, South India. JI Minerals 2021, 11, 1370-83. DOI: https://doi.org/10.3390/min11121370 
• Brian O'Driscoll1*, Julien Leuthold, Davide Lenaz, Henrik Skogby, James MD Day and Jacob Adetunji (2021). Melt Percolation, Melt-Rock Reaction and Oxygen Fugacity in Supra-Subduction Zone Mantle and Lower Crust from the Leka Ophiolite Complex, Norway. Journal of Petrology Volume 62, No. 11, 1-26. DOI: https://doi.org/10.1093/petrology/egab078 
• John Stubbs and Jacob Adetunji (March 2021) Addenum to: Paying for end-of-life care in the UK. https://www.researchgate.net/publication/354167283_Addendum_to_Paying_for_end_of_life_care_in_the_UK 
• Malose M. Langa, Pedro. J. Jugo, Matthew I. Leybourne, Danie F. Grobler, Jacob Adetunji, Henrik Skogby. (March 2021) Chromite chemistry of a massive chromitite seam in the northern limb of the Bushveld Igneous Complex, South Africa: Correlation with the UG-2 in the eastern and western limbs and evidence of variable assimilation of footwall rocks. Mineralium Deposita. Vol. 56 (6), 31-44. DOI: http://dx.doi.org/10.1007/s00126-020-00964-y 
• John Stubbs, Jacob Adetunji (Nov 2020). Paying for end of life care homes in the UK, A Mathematical Model. In The Mathematical Gazette. Vol., 104 Number 561 pp. 495-506. DOI: https://doi.org/10.1017/mag.2020.103 
• Gismelssed A.M, Okunlola O.A, Al-Rawas A.D, Yousif A A, Oyedokun M.O., Adetunji J., Widatallah H.M, Elzain M. E. (19 Dec 2019) Characterization of a Newly fallen Nigerian meteorite. JI Hyperfine Interactions, Vol, 241: Article number 13 (2020). DOI: https://doi.org/10.1007/s10751-019-1683-7 
• Adetunji, Jacob (July 2018). A simple unified equation for accurate and rapid quantification of Fe3+/∑Fe obtained from room temperature Mossbauer spectroscopic measurements. Preprint online on 11 July 2018/ DOI: http://dx.doi.org/10.20944/preprints201806.0441.v2 
• Hugh Rollinson, Jacob Adetunji (Sept 2017). Ionic Radii.  Chapter in Encyclopedia of Geochemistry: (A comprehensive reference source on the chemistry of the Earth Sciences Series). Ed: William M. White. DOI: 10.1007/978-3-319-39193-9_340-1
• Szilas, K., van Hinsberg, V., McDonald, I., Næraa, T., Rollinson, H., Adetunji, J., Bird, D., (June 2017). Highly refractory Archaean peridotite cumulates: petrology and geochemistry of the Seqi ultramafic complex, SW Greenland. Geoscience Frontiers online. DOI: 10.1016/j.gsf.2017.05.003
• Hugh Rollinson, Jacob Adetunji, Davide Lenaz, Kristoffer Szilas. (2017). Archaean chromitites show constant Fe³⁺/ΣFe in Earth's asthenospheric mantle since 3.8 Ga. Lithos, Vol. 282–283, pp316–325. DOI: https://doi.org/10.1016/j.lithos.2017.03.020
• Jennifer Huggett, Jacob Adetunji, Fred Longstaffe, David Wray. (2017). Mineralogical and Geochemical Characterisation of warm water, shallow marine glaucony from the tertiary of the London Basin. Clay Minerals. Vol. 52, Issue 1, pp 25-50.. Mineralogical Society: ISSN 0009-8558 ISSN 0009-8558. DOI: https://doi.org/10.1180/claymin.2017.052.1.02
• Huggett, J., Cuadros, J., Gale, A. S., Wray, D., Adetunji, J. (2016). Low Temperature, Authigenic Illite and Carbonates in a mixed Dolomite-Clastic Lagoonal and Pedogenic setting, Spanish Central System, Spain. Applied Clay Science. Vol. 132-133 p296-312. DOI: 10.1016/j.clay.2016.06.016
• Stubbs, J. and Adetunji, J. (July 2016). UK pension changes in 2015: some mathematical considerations. The Mathematical Gazette. Vol. 100, Issue 548, pp193-202. DOI:10.1017/mag.2016.55
• Rollinson, Hugh, Adetunji, Jacob (June 2016) Comment on ‘Podiform chromitites do form beneath mid-ocean ridges’ by Arai, S. and Miura, M. Jl  Lithos, Vol. 254-255, pp 131-133. DOI: 10.1016/j.lithos.2015.10.023
• Rollinson, H., Adetunji, J. (2015) Chromite in the mantle section of the Oman Ophiolite: implications for the tectonic evolution of the Oman ophiolite. Acta Geologica Sinica Vol. 89 Suppl. 2. p 73-76. DOI: 10.1111/1755-6724.12308_44/epd
• Rollinson, H., Adetunji, J. (2015). The geochemistry and oxidation state of podiform chromites from the mantle section of the Oman ophiolite: review. Gondwana Research. Vol. 27, Issue 2. 543-554.  DOI: 10.1016/j.gr.2013.07.013
• Adetunji, J. (2014) ⁵⁷Fe Mössbauer spectroscopy investigation of iron oxidation states in the Harmattan dust nutrient contribution to the West African soils. Atmospheric Environment Vol. 98 591-598. DOI: https://doi.org/10.1016/j.atmosenv.2014.09.025
• O’Driscoll, B., Clay P. L., Cawthorn, R. G., Lenaz, D., Adetunji, J., Kronz, A. (2014) Trevorite: Ni-rich spinel formed by metasomatism and desulfurization processes at Bon Accord, South Africa. Mineralogical Magazine, Vol. 78 (1), pp. 145–163. DOI: 10.1180/minmag.2014.078.1.11
• Lenaz, D., Adetunji, J. and Rollinson, H. (2014). Determination of Fe³⁺/SFe ratios in chrome spinels using a combined Mössbauer and single-crystal X-ray approach: application to chromitites from the mantle section of the Oman ophiolite. Contrib Mineral Petrol. Vol. 167,Issue: 1, Article  958. DOI: 10.1007/s00410-013-0958-2
• Adetunji, J., Everitt, S. and Rollinson, H. (2013) New Mössbauer measurements of Fe³⁺/ΣFe ratios in chromites from the early Proterozoic Bushveld Complex, South Africa. Precambrian Research Vol. 228 pp194-205. DOI:10.1016/j.precamres.2013.01.007
• Rollinson, H., Adetunji, J. (2013) Mantle Podiform chromatites do not form beneath mid-ocean ridges: A case study from the Moho transition zone of the Oman Ophiolite. Lithos Vol 177 pp 314-327. DOI: 10.1016/j.lithos.2013.07.004
• Rollinson, H., Adetunji, J., Yousif, A. A. and Gismelseed, A. M. (2012) New Mössbauer measurements of Fe³⁺/(SumFe) in chromites from the mantle section of the Oman ophiolite: evidence for the oxidation of the sub-oceanic mantle. Mineralogical Magazine Volume: 76 Issue: 3 Pages: 579-596. DOI: 10.1180/minmag.2012.076.3.09
• Rollinson, H., Adetunji, J., Greenwood, M. and Souch, G. (2012). Derby Dust: geochemical characterisation of airborne inorganic particulate matter in western Derby.  Mercian Geologist: Volume: 18 No 1 p 41-46
• Ferrow, E, Adetunji, J. and Nkoma, J. S.  (2006) “Characterization of pyrrhotite in Cu-Ni-ore bodies from mines in Botswana, by Mössbauer spectroscopy, X-ray diffraction and thermo-magnetometry” Eur. J. Mineral. 18 653-664. DOI:10.1127/0935-1221/2006/0018-0653
• Adetunji, J., Dronsfield, A. and Morris, P. (2005) “Infra-red Spectroscopy – Why did it take so long?” Jl Education in Chemistry 42 (2) 50-53
• Jancik, D., Mashlan, M., Zhobril, R., Adetunji, J. and Nomura K. (2005) “A new fast type of Mossbauer Spectrometer for rapid determination of iron-bearing minerals used in the paint the industry”. Czech J. Phys 55 (7): 803-811.   DOI: 10.1007/s10582-005-0082-2
• Adetunji, J., Williams J. M. and Mehra, A. (2002).  “Fe-57Mössbauer spectroscopic investigation of some coals of geographically different provenance and their fly ashes”.  Proc. ICAME-2001, Eds Thomas M.F., Williams, J. M. and Gibb, T. C. in Hyperfine Interactions C- 5,379 –382 
• DOI:http://dx.doi.org/10.1007/978-94-010-0281-3_94
• Aghamohammadzadeh, H., Williams, J. M. and Adetunji, J. (2002). “A Mössbauer study of steel and its ore originating from Northern Iran”. Proc. ICAME-2001, Eds: Thomas M.F., Williams J. M. and Gibb T. C. in Hyperfine Interactions C- 5 pp 511-514. DOI: http://dx.doi.org/10.1007/978-94-010-0281-3_126
• Adetunji, J. and  Dronsfield, A. (2000)  “The beginnings of Mossbauer   spectroscopy”.  Jl  Education in Chemistry Vol 39 No. 4  97-100www.rsc.org/education/eic/issues/2002July/july2002Adetunji.asp
• Williams, J. M., Adetunji J. and Gregori, M. (2000). “Mössbauer   spectroscopic determination of magnetic moments of Fe³⁺ and Co²⁺ in substituted barium hexaferrite, Ba(Co,Ti)_xFe_(12-2x)O₁₉”  Jl.  Mag. and Mag. Materials Vol. 220 (2) 124-128. DOI: 10.1016/S0304-8853(00)00458-3
• Gregori, M., Adetunji J., Williams, J. M. (1998). ‘’ ⁵⁷Fe Hyperfine Interaction Parameters in Co²⁺ , Ti²⁺  - Substituted M-type barium hexaferrite’’. In the Proc. of  ICAME’97  Eds.: E. Baggio-Saitovich, H. Reehenberg and R.B. Scorzelli: Hyperfine Interactions C- 3 pp185-188.