I could not find any 40 GB network controller for R7525. There are 25 and 100 Gig network controllers supported on R7525. You can refer below link on different types of PCIe card supported on R7525

https://www.dell.com/support/manuals/en-us/poweredge-r7525/r7525_ism_pub/expansion-card-installation-guidelines?guid=guid-93036e1c-fa08-4abc-bca5-80da152730d0&lang=en-us 

Hi the part you are looking for may be this.

part #:9FTMY    /  Part Desc.:CRD,NTWK,100G,CX5,DP,QSF,MLX,L  / Network Card, PCIe, ConnectX-5 Dual Port 100 GbE QSFP Network Adapter, Half Height

Just to add: my reasoning behind:

https://dell.to/3uiZZN8

https://dell.to/3DQwsNZ

Thanks for the response from you both! I will see if the boss wants to experiment with one or both of the  100Gb cards or just use the 25Gb card that is in there.

Jeff