Journal of Materials Science and Engineering A 8 (3-4) (2018) 65-69 doi: 10.17265/2161-6213/2018.3-4.004 Validity of Post Constraint of Electromagnetism in Multiferroic Materials Upasana Panigrahi and Shuichi Torii Department of Advanced Mechanical System, Kumamoto University, Kumamoto 8600862, Japan Abstract: We present a framework for modeling the boundary-value problem (frequency driven) for homogeneous multiferroic material under the validity of post constraint and apply it to fundamental differential equation of electromagnetism in valid new regimes (boundary conditions for material with simultaneous electric and magnetic order). Three facets of the model are addressed, which explicitly respect the validity of post constraint of modern electromagnetism. First, AFM (antiferromagnetic) ordering and magneto electric coupling are explained. Second, the energetic anaysis of multiferroic is expressed for ferroic-electric ordering. Third, the conflict of fundamental differential electromagnetism in multiferroic material under explicit application of boundary condition is resolved. Key words: Multiferroic, antiferriomagnetic ordering, electromagnetic theory, post constraint, boundary conditions, Tellegen parameter. Nomenclature H: Exchange interaction energy C: Elastic stiffness B: Magnetic induction H: Magnetic field E: Electric field D: Electric displacement P: Polarisation M: Magnetisation Greek letters κ: Dielectric coefficient ω: Angular frequency ν: Impermeability coefficient ζ m: Demagnetisation ζ p: Depolarisation 1. Introduction Multiferroic material has boomed enormously in recent years. Exponent growth in the development of accurate theoretical method accompanying the sophisticated synthesis techniques in both solid route Corresponding author: Upasana Panigrahi, Ph.D. student, research fields: advanced mechanical systems, nanofulid, multiferroic material, thermal engineering and theoretical physics. methods like mechanical activation, sintering; and wet chemical methods like sol-gel method, pulsed laser deposit, liquid chemical epitaxy, hydrothermal synthesis etc; along with characterisation brings in the study of various types of multiferroic oxides [1-5]. The discussion of multiferroics is fascinating since this is rich in variety of physical mechanisms underplaying simultaneously evolving captivating scenario when ferroelectric and magnetic order simultaneously exhibit along with ferroelasticity [6-9]. This paper addresses the genesis of the post constraint of electromagnetic constitution relation of multiferroic material medium. The post constraint is the structural constraint with the linear medium exhibiting the magneto-electric coupling [10, 11]. With the origination from the microscopic nature of primitive electromagnetic fields and Lorentz covariance of the Maxwell equations, the post constraint has 35 independent complex-value parameters [12, 13]. We analyse the energetic analysis of multiferroic material for ferroelectric ordering and anti-ferromagnetic order with magneto electric coupling. We then have presented a framework for developing the validity of post constraint of multiferroics. D DAVID PUBLISHING