ABSTRACT
Bismuth ferrite (BiFeO3) is the only well-known room-temperature magnetoelectric multiferroic (MM) material [1, 2]. In MM materials, both ferroelectricity and antiferromagnetism can coexist in a coupled fashion. Such MM materials will be very useful for both magnetic detectors and multistate memory devices. To better exploit the functionalities of the MM materials, the major challenge today has been the synthesis of nano bismuth ferrite (NBFO). Further, ferroelastic ordering has been observed due to plastic deformation in La-based perovskites [3, 4] through studies on mechanical hysteresis. Despite the wealth of literature [5-7], there is no report on the nanomechanical behavior of NBFO samples prepared by sol-gel technique [8], as mentioned in Chapter 9. It is the high porosity of nanomaterials that becomes inhibitive to carry out indentation. Therefore, our main focus in this chapter will be the systematic nanoindentation study at ultralow loads on very low-temperature (300°C), partially annealed green NBFO pellets formed at 600-800 MPa pressure [8]. To the best of our knowledge, this is the first time that nanoindentation has been carried out on a green ceramic nano MM material pellet.
