Polarised-Light and Electron Microscopy of the Static Domain Structure of Ferroic Mn₃B₇O₁₃Br Boracite at Room Temperature

Abstract

The static domain structure of ferroic Mn₃B₇O₁₃Br, abbreviated in what follows as Mn-Br, synthetic boracite crystals have been analysed by polarized-light microscopy (PLM) and by field emission scanning electron microscopy (FE-SEM) at room temperature. As most boracites, Mn-Br possess dielectric, elastic, magnetic and optical properties of unusual interest. The stable phase of Mn-Br at room temperature has orthorhombic symmetry (point group mm2) which transforms to a cubic phase (space group ${\displaystyle F\overline{4}3c}$) when heating the crystal above 540 K. Optical examination of all samples grown by chemical transport reactions showed a bulky domain configuration which was resolved in a fine lamellar configuration under the electron microscope.

Keywords:

• Ferroic domains
• boracites
• polarised-light microscopy
• field emission scanning electron microscopy

Funding

The authors wish to thank Coordinación General de Cooperación e Internacionalización, Coordinación General Académica and Centro Universitario de Ciencias Exactas e Ingenierías all from Universidad de Guadalajara, México for economical support thru Pifi, ProSni and fondos concurrentes programs. AGCG would like to acknowledge the ICTP Trieste-Italy for financial support of Latin-American Network of Ferroelectric Materials (NET-43).