Negative heat capacity is a phenomenon in which the temperature of a system decreases when it absorbs heat, and increases when it releases heat. This is in contrast to traditional heat capacity, where the temperature of a system increases when it absorbs heat.
Negative heat capacity is caused by certain materials or systems having a higher number of accessible energy states at higher temperatures than at lower temperatures. This leads to a decrease in temperature when heat is added, as the energy is distributed among a greater number of states.
A thermal reservoir is a large system or environment that is able to maintain a constant temperature, and can supply or absorb unlimited amounts of heat without changing in temperature. This allows for a stable heat source or sink in thermodynamic processes.
Negative heat capacity has practical applications in refrigeration and cryogenics, as it allows for cooling without the need for external energy sources. It also has implications in materials science and can lead to more efficient heat storage and transfer systems.
No, negative heat capacity does not violate the laws of thermodynamics. These laws still hold true, but negative heat capacity is a result of systems or materials with unique properties that follow these laws in a non-traditional way.