18.6K single-stage high frequency multi-bypass coaxial pulse tube cryocooler

Optimization of the Magnetocaloric Effect in Low Applied Magnetic Fields in LnOHCO3 Frameworks

“…While cryogen-free cryocoolers are available as alternatives for cooling to the liquid He temperature regime their efficiency at such temperatures is particularly low, typically only a couple of percent . It is therefore important to investigate if MCE materials can be optimized to have high performance in low applied magnetic fields between 4 and 20 K. Such materials could then be used for cooling in the liquid He regime likely in conjunction with, more efficient, higher temperature cryocoolers. , …”

“…8 It is therefore important to investigate if MCE materials can be optimized to have high performance in low applied magnetic fields between 4 and 20 K. Such materials could then be used for cooling in the liquid He regime likely in conjunction with, more efficient, higher temperature cryocoolers. 9,10 For such optimization of MCE materials, it is becoming apparent that it is important to not just achieve a high density of magnetic cations but also to control the magnetic interactions in these compounds. It is well-established that frustrated magnetic interactions can enhance MCE behavior, including in the benchmark oxide Gd 3 Ga 5 O 12 ; 11−13 frustrated interactions enable a higher density of magnetic cations to be incorporated in a phase that remains paramagnetic to low temperature than is possible in the alternative "dilute" magnetic salts, which depend on having well separated magnetic centers to remain paramagnetic.…”

Structure and magnetic properties of the AB(HCO2)3 (A = Rb+ or Cs+, B = Mn2+, Co2+ or Ni2+) frameworks: probing the effect of size on the phase evolution of the ternary formates

“…11 Indeed the situation is even more complex than this as chiral hexagonal structures containing HONH 3 + and NH 2 NH 3 + cations have tolerance factors as high as 0.85, well into the range of the Perovskite I structure. 13,19,21 Clearly other factors beyond ionic radii will influence the structures adopted by some of these materials e.g. the specific shape of the molecular guest and the precise hydrogen bonds it forms with frameworks may favour some structure types over others.…”

Development of a high-frequency coaxial multi-bypass pulse tube refrigerator below 14K

“…Besides, multibypass can increase the amplitude of pressure oscillating in the pulse tube and adjust the phase relationship, which is similar to what double-inlet does. Therefore, it is concluded that multibypass is a potential substitution for double-inlet and even surpasses the effect of double-inlet in certain cases [6]. However, double-inlet still works in this case.…”