This book comprehensively introduces sustainable nature of the perovskite multiferroic materials. It covers detailed information about single-phase and composite perovskite-based multiferroics, nanostructures of multiferroics and the structural aspect. It majorly focuses on the application part of the newly emerging non-toxic perovskite multiferroics, green synthesis techniques and energy harvesting applications. The applications mainly concerning with energy harvesting, spintronics, photovoltaic and photo-catalysis, sensors, gyrators, gradiometer, transducers and memory storage devices have been provided in detail. In the recent past, the multiferroic materials are the center of attention with new breakthroughs in the above applications, including quantum computing, and comprises both scientists and young researchers as inspiration as well as critical ideas to develop new work in this area. As far as the lead-free multiferroic materials are concerned, the present book includes information on eco-friendly smart materials, as these are being majorly used as sensors and actuators in nano- or micro-electromechanical systems. The magnetoelectric coupling-based nano or micro-electromechanical devices are established to exhibit high-quality factor and can be combined with radio frequency integrated circuits. This book offers thorough exploration of green, non-toxic and viable commercial technology on multiferroic and magnetoelectric materials. The simulations based on the multiferroic materials, quantum criticality and emergent ideas of quantum electromagnets are also the center of attention of this book. In conclusion, this book is the perfect need of the materials scientists and should receive a place in the libraries of solid-state physicists and chemists who are looking to understand multiferroics from basics to latest applications. All the researchers working in the area of energy harvesting, spintronics, photovoltaic and photo-catalysis, sensors, gyrators, gradiometer, transducers, memory storage devices and quantum computing will benefit from this book.