Dr. Robert Mayanovic Research Group - Physics, Astronomy and Materials Science Department

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Inorganic magnetic nanostructured materials

Recent group members

Md. Delower Hossain, MS Materials Science MSU, PhD Penn State U.
Samiul Hasan, MS Materials Science MSU, PhD U. of South Carolina
Tamzid Ibn Minhaj, MS Materials Science MSU, currently PhD North Carolina State U.
Nazmul Alam, MS Materials Science MSU, PhD U. Delaware
Abdullah Al Shafe, MS Materials Science MSU, PhD North Carolina State U.
Md. Tauhidul Islam, MS Materials Science MSU, currently PhD Case Western U.
Zach Leuty, MS Materials Science MSU, PhD Arizona State U.
Ashif Anwar, MS Materials Science MSU
Mohammad Uddin, MS Materials Science MSU, currently PhD Purdue U.
Farhan Ishrak, MS Materials Science MSU, currently PhD North Carolina State U.

Inverse core-shell nanoparticles, that have an antiferromagnetic (AFM) core covered by a ferromagnetic (FM) or ferrimagnetic (FiM) shell, are of considerable current interest due to the tunability of their magnetic properties. Investigations of core-shell nanoparticles (CSNs) are of interest due to their potential applications in magnetic random access memory, spintronic devices and biomedical applications. We have investigated several inorganic nanoparticulate heterostructures, including Cr2O3/MxCr2-xO3, where M is Mn, Fe, Co, Ni, and Cu, NiO/NixMn1-xO, NiO/Mn3O4, NiO/CoMn2O4, and CoO/NiFe2O4 systems. These are being investigated primarily for their exchange bias properties that occurs at the AFM/FM or AFM/FiM interface. The NiO- and CoO-based nanoparticles have the rock-salt/spinel crystal structure. Synthesis of these nanoparticles is made using a two-step process. The Cr2O3, NiO, or CoO core nanoparticles are first synthesized using thermal decomposition of an appropriate precursor. Subsequently, the nanoparticulate overlayer is grown over the core nanoparticles using one of several different methods, including hydrothermal, rotary evaporation, and refluxing synthesis.

The size and pH level of hydrothermal synthesis have been investigated as parameters that affect the magnetic and structural properties of the heterostructured nanoparticles. The pH level plays an important role in governing the surface energy of the precursor nanoparticles and thereby the surface morphology. We discovered that the magnetic coercivity and exchange bias of NiO/Mn3O4 core-island nanocrystals varied systematically with pH of the hydrothermal solution. Very robust maximal values (6 KOe and 3 KOe, respectively) for the coercivity and exchange bias field were measured for the nanocrystals.

In addition to the nanoparticles, students are also involved in the synthesis and investigation of nano-sized thin films having a similar arrangement as the core-shell nanoparticles: for example, we have synthesized NiO/NixMn1-xO bilayers grown on MgO and Al2O3 crystalline substrates. The thin film bilayers were found to exhibit exchange bias characteristics that are similar to those of the NiO-based core-shell nanoparticles. In a separate study, pulsed laser deposition (PLD) was used to grow ferromagnetic FePt thin film layers interfaced with antiferromagnetic NiO thin film layers, on the (100) surface of MgO substrates. It was determined that the magnetic spin-spin interactions at the interface between the FePt and NiO thin films results in the orthogonal/perpendicular exchange bias (EB). The perpendicular EB is attributed to the magnetocrystalline anisotropy of the FePt layer and the preferential orientation of the NiO antiferromagnetic spin-populated lattice. These thin film systems potentially lend themselves more directly to potential device applications because of the ease of patterning of such thin film heterostructures. In-house characterizing instruments, namely SEM, SQUID, XRD and Raman spectroscopy are used to study the structural and magnetic properties of the nanoparticle and thin film samples. In addition, high-resolution transmission electron microscopy (HRTEM) and X-ray photoemission spectroscopy (XPS) are used to investigate the structural and surface chemical properties of the nanoparticle and thin film samples.

Chitosan nanoparticles for drug delivery

Recent group members

Rejeena Jha, MS Materials Science, currently PhD U. Arkansas
Markos Georgy, currently MS Materials Science
Hyrum Harlow, BS Physics

Chitosan is a natural material derived by N-deacetylation of chitin, which is derived from the shells of crustaceans, including lobsters, shrimp, and crabs, and certain fungi. Chitosan (CS) is a polysaccharide derived by the N-deacetylation of chitin. Chitosan is a linear copolymer consisting of glucosamine and N-acetyl-glucosamine units wherein the repeatability of the glucosamine-based units is determined by the degree of deacetylation. The chitosan nanoparticles (CS-NPs) are prepared in our lab using the ionic gelation method and functionalized using various surfactants and polymers. We have used polyethylene oxide (PEO) and polypropylene glycol (PPG), as well as a diblock copolymer combination of PEO and PPG to functionalize the CSNs. The incorporation of polymers and surfactants can improve the solubility, hemocompatibility, and bodily-fluid stability of the CSNs. The ultimate goal is to improve the drug delivery capacity of the CSNs to the human body.

In our recent study, the average size of the CS-NPs from TEM imaging was in the 11.3 to 14.8 nm range. XRD and high-resolution TEM (HRTEM) analyses showed that the CSNs are semi-crystalline. Functionalization with PEO-PPG resulted in a significant increase in their degree of crystallinity of the CS-NPs. The incorporation of tripolyphosphate (TPP) along with enhanced hydrogen bonding in the CS-NPs functionalized with PEO-PPG was confirmed from FTIR measurements. HRTEM analysis revealed that the degree of crystallinity of CS-NPs is distributed heterogeneously, with the more crystalline nanoparticles trending toward a prismatic-shaped morphology: The less crystalline or amorphous nanoparticles trend toward a pseudo-spherical morphology. The findings provide valuable insights into potential pathways toward optimization of the structural characteristics of functionalized CS-NPs for enhanced efficacy and/or tunability for drug delivery.

Insights on the dissolution of water in an albite melt from a direct structural analysis

Recent group members

Devon Romine, MS Materials Science, currently physics instructor MSU
Collaborator: Dr. Alan Anderson, St. Francis Xavier University, Antigonish, Nova Scotia, Canada
Collaborator: Dr. Chris Benmore, Advanced Photon Source, Argonne National Lab, Argonne, IL

Other recent group members

Diwash Dhakal, MS Materials Science MSU, PhD Univ. of Washington
Nadib Akram, MS Materials Science MSU, PhD Univ. of Connecticut

A direct analysis of water-saturated albite melt reveals new details on how water modifies the network structure of felsic melts.

The incorporation of water in silicate melts plays an important role in a number of geological processes, including ascent and emplacement of granitic magmas, magma differentiation, and volcanic eruptions. Detailing the precise mechanism of dissolution of water in silicate melts has been elusive because such systems need to be directly probed under high temperatures and pressures. Direct information on the structure at the molecular and intermediate level is required to obtain a better understanding of the silicate liquid-water reactions and melt structure modifications stemming from the dissolution of water. The albite – water system at high temperatures and pressures is a close analogue of hydrous granite melts. In this work we provide the first direct structural analysis of a hydrous silicate melt. High energy X-ray diffraction measurements using a synchrotron source were made on a hydrous albite melt at 800 °C and 300 MPa. The analysis was augmented using Molecular Dynamics (MD) simulations.

Our results confirm that the extent of depolymerization exceeds previous estimates and discount previous suggestions for the dissociation of the Al3+ and Na+ ions from the network structure due to water incorporation. Interestingly, whereas the silicon – oxygen bonds are broken at the bridging sites of the network structure upon reaction with H2O, resulting in subsequent silicon – hydroxide formation, we find negligible evidence for aluminum – bridging – oxygen bond breaking and aluminum – hydroxide formation. Alkali metals including sodium are well known network structure modifiers in aluminosilicate glasses but considerably less is known about their structural role in hydrous aluminosilicate melts. Our results show that the Na+ ion remains a network modifier and undergoes more extensive bonding with non-bridging oxygens, in comparison to bonding with bridging oxygens, at shorter bonding distances (6% reduction) in the network structure of the water-incorporated albite melt.

The results presented in our work on the modifications of the intermediate structure of albite melts upon incorporation of water will need to be incorporated in future models of water dissolution in silicate melts.

Select publications (2018-2024)

Students' names appear in bold below:

X. Yuan, Z. Yang, R.A. Mayanovic, Z. Hou, Experimental evidence reveals the mobilization and mineralization processes of rare earth elements in carbonatites, Science Advances 10, eadm9118(1-14pp) (2024).

R. Jha, H. Harlow, M. Benamara, R.A. Mayanovic, On the structural and molecular properties of PEO and PEO-PPG functionalized chitosan nanoparticles for drug delivery, Bioengineering, 11, 372 (2024).

R. Jha, R.A. Mayanovic, A Review of the preparation, characterization, and applications of chitosan nanoparticles in nanomedicine, Nanomaterials 13, 1302 (2023). https://doi.org/10.3390/nano13081302.

R.A. Mayanovic, A.J. Anderson, D. Romine, C. Benmore, Insights on the dissolution of water in an albite melt at high pressures and temperatures from a direct structural analysis, Scientific Reports 13, 4012 (2023). https://doi.org/10.1038/s41598-023-31043-7.

F. Ishrak, R.A. Mayanovic, M. Benamara, Size-Dependent magnetic properties of Mn-Co-NiO based heterostructured nanoparticles, AIP Advances 13, 025209 (2023).

M.S. Uddin, R.A. Mayanovic, M. Benamara, On the synthesis and characterization of bimagnetic CoO/NiFe2O4 heterostructured nanoparticles, AIP Advances 13, 025314 (2023).

A. Al Shafe, M.D. Hossain, Mourad Benamara, V. Roddatis, R.A. Mayanovic, Defects and surface chemistry of novel pH-tunable NiO-Mn3O4±MnxNi1-xO heterostructured nanocrystals as determined using X-Ray photoemission spectroscopy, Journal of Electronic Materials, 52, 1193–1202 (2023). https://doi.org/10.1007/s11664-022-10047-5

A. Al Shafe, M.D. Hossain, R.A. Mayanovic, V. Roddatis, M. Benamara, Tuning exchange coupling in NiO-based bimagnetic hetero-structured nanocrystals, ACS Appl. Mater. Interf., 13, 24013−24023 (2021).

A. Kalintsev, A. Migdisov, C. Alcorn, J. Baker, J. Brugger, R.A. Mayanovic, N. Akram, H. Xu, H. Boukhalfa, F.Caporuscio, H. Vishvanatan, C. Jove-Colon, Y. Wang, E. Matteo, R. Roback, Uranium carbonate complexes demonstrate drastic decrease in stability at elevated temperatures, Nature’s Commun. Chem., 4, 1–8 (2021).

D. Dhakal, N. Akram, R.A. Mayanovic, H. Boukhalfa, H. Xu, A study of uranyl (VI) chloride complexes in aqueous solutions under hydrothermal conditions using Raman spectroscopy, MRS Advances, 5, 2623-2629 (2020).

D. Dhakal, R.A. Mayanovic, J.L. Baker, H. Boukhalfa, H. Xu, C.-J. Sun, Design of a containment apparatus for synchrotron XAS measurements of radioactive fluid samples under high temperatures and pressures, Rev. Sci. Instrum., 90(8), 083108 (2019).

A.J. Anderson, R.A. Mayanovic, T. Lee, The local structure of Ta(V) aqua ions in high temperature fluoride- and chloride-bearing solutions: Implications for Ta transport in granite-related postmagmatic fluids, Can. Mineral., DOI: 10.3749/canmin.1900022, 57, 843-851 (2019).

Z.B. Leuty & R.A. Mayanovic, Investigations of the magnetic perpendicular exchange bias in L10 FePt/NiO bilayer thin films, MRS Advances, 3, 2893–2898 (2018).

Samiul Hasan, R.A. Mayanovic, M. Benamara, Investigation of novel inverted NiO@NixCo1-xO core-shell nanoparticles, AIP Advances 8, 056305 (2018).

M. D. Hossain, R.A. Mayanovic, S. Dey, R. Sakidja, M. Benamara, Room-Temperature ferromagnetism in Ni(II)-chromia based core-shell nanoparticles: Experiment and first principles calculations, Phys. Chem. Chem. Phys., 20, 10396-10406 (2018).

M. D. Hossain, R. Sakidja, R.A. Mayanovic, R. Wirth, M. Benamara, Magnetic properties of core-shell nanoparticles possessing a novel Fe(II)-chromia phase: An experimental and theoretical approach, Nanoscale, 10, 2138 – 2147 (2018).