The Dresden High Magnetic Field Laboratory (HLD) is a pulsed-field user facility which currently operates ten experimental chambers equipped with a variety of pulsed magnets energized by two capacitor banks with maximum stored energies of 50 and 14 MJ at 24 kV maximum operational voltage. The magnets support a broad range of experiments in pulsed magnetic fields for user and in-house research. In the first part of my talk I will present some recent developments at the HLD.
Spin-lattice effects play an important role in many magnetic materials, frequently leading to novel phases and phase transformations. In this presentation, I give some examples of such effects studied in frustrated magnets characterized by competing interactions. The delicate balance between these interactions can be easily disturbed by the application of strong magnetic fields leading to field-induced phase transitions. The phase transformations and the related critical phenomena in magnetic systems are fruitful grounds for ultrasound experiments which provide valuable information on the spin-strain coupling. I discuss the sound-velocity and sound-attenuation results obtained in magnetic fields up to 87 T for some selected materials with a magnetic pyrochlore lattice, such as CdCr2O4 and CoCr2O4 which exhibit unusual phase transitions and extended metastable magnetostructural states. I will show that the spin-strain coupling is crucial and determines the underlying physics of the frustrated magnetic materials.